There's a lot of overlap going on between Additions and QoL, so let's try to clarify it a bit.
QoL is mainly for UI and display tweaks to show information that isn't available, but should be.
Small tweaks also go there (Example: showing a button for a feature that's already in the game, etc)

Additions is for major gameplay additions and gameplay tweaks in general.

In no particular order:

@COMF400 移動.ERB, COMF420 る～ことと話す.ERB
	HITOSAGASI(,1) function modification to allow checking for other areas
	
@DRAW_MAP.ERB
	Highlight characters on adjacent spots on the map regardless of Whereabouts Sense (and visibility)

@強くてニューゲーム.ERB
	@KOJO_MULTIPLE - Allow choosing dialogue for characters with each update without triggering reset for every character by @sequentialaccess

@MOVEMENT_SUB.ERB
	Show when characters separate from you when leading them. When flag expires, the message is shown.
	
@ROOMSETTING_1, 5, 6, 7, 8, 10
	Reset SUMIKOMI_ROOM, to later display available rooms for lodgers in MAP_MANAGE.ERB, @物件データ
	
@MAP_MANAGE.ERB
	Ask if you'd like to renew Omikuji contract from Reimu when moving out. @Qol_MoveIn_Omikuji
	By default it resets silently and you have to seek Reimu again to resume the contract.
	
@NEWGAME_BONUS.ERB
	Replace the list of characters with LIST_SEARCHABLE function which supports search by name.
	
@NEWGAME_VIRGINITY.ERB
	Replace original virginity setting menu with a custom one
	
@SHOP.ERB, PRINT_STATE2.ERB
	Show current home location and sleeping position
	
@SHOP_住環境設定.ERB
	Replaces original menu for changes living quarters with a custom one @QoL_LiveIn.ERB.
	Much more information and lets you choose your landlord.
	
@LIST.ERB
	Fully custom character screen and character list.
	@キャラリスト functions add new filters for LIST.ERB, showing characters with races that qualify for impregnation achievements + a general one (humans).
	
@QoL_Roster-Stalker.ERB
	Adds code for a new list of all characters with their pictures ("Roster").
	
@QoL_COMF418 家庭菜園
	Replaces original COMF418 for Kitchen Garden action.
	New menu doesn't kick you out from the garden screen from each action, and there's a lot of buttons to make the gardening less of a chore.
	Made it so you can have 10 gardening plots in total;
	Keep Earth God's blessing active so it keeps every plot moisturized;
	
	Related code in @YASAI.ERB
		Earth will be moistened after dry counter, preventing premature withering
	
@QoL_DateEvent.ERB
	Replaces original DateEvent function, functionally the same, provides more information.
	Gifts from characters are given earlier to increase the chance to receive them a bit.
	Moved confession question to a function
	
@QoL_FishSpotList.ERB
	Shows list of fish in a current fishing spot (similar to what foraging has)
	Adds a button to main menu to see fishing spots, checks for knowledge to see fishes
	
@QoL_UnlockNotify.ERB
	Notifies the player about potential unlocks after fulfilling the conditions (befriending characters and etc)
	
@QoL_COM490_ITEMMENU.ERB
	Replaces the menu part for item usage menu in COMF490
	
@QoL_Misc.ERB
	Assortment of things.
	@BATHED shows your character's bathing status to be aware when you can bathe next time.
	;Code in @EVENTTRAIN shows the approximate Earth score at the beginning of each day if player has Suwako's blessing (Earth God's Blessing)
		---> Disabled as flag usage has changed into personal fortune, changed to Tewi's Fortune Crest instead
		
@COMF400 移動.ERB
	Prevents you from stopping each time when meeting another character during Time Stop, less annoyance
	
@COMF482 追う.ERB
	Allows [Follow] command to be available during Time Stop
	
@USERCOM_コマンド表示処理.ERB, @USERCOM.ERB, @COMF420 る～ことと話す.ERB
	Allow whereabout sense to be active outside of main map where player lives
	
@DANMAKU.ERB
	When using [Epitaph] or [King Crimson], let player choose whether to use TSP to dodge or not instead of always doing it
	Can be useful when you want to trade life for more bombs or when you know that you can't win this round without wasting TSP
	
@A_PEARL.ERB
	Notify the player if the inserting character can't remove the plug at the current spot. Move to a safe place for it to happen.
	Added exp on insertion, and exp when struggling to hold the plug in.
	
@日時天候管理.ERB
	Added an option to renew watering services for the Kitchen Garden when it expires
	
@PANTS.ERB
	Shows if you got special panties from the character (@PANTY_SPECIAL_GET)
	
@AFTERTRA.ERB
	Show when characters acquire new favorite positions
	
@APPEND_SYS.ERB
	Added paging menu for characters since it tends to get pretty long
	
@COMF464 特殊地域間移動
	Allow cableway to work up to 21:00 instead of 17:00 at a higher fee (move to COM branch instead?)
	
@SHOP_ITEM.ERB
	Print item description when buying, based on old custom code that got purged accidentally
	The used functions are contained in Translated branch (PRINT_ITEM_DESC, etc)

@OPTION.ERB, TRACHECK_好感度上昇処理.ERB, TRACHECK_信頼度上昇処理.ERB
	Option to always show favor/reliability gain regardless if source gain was achieved
	
@INFO.ERB
	Show when characters are going to work/Working characters/Characters that'll go working right away if they leave their private room
	Always show an exclamation point for anger when it's below the first threshold (<200)
	Show Thermal Jar status if it's on you for cooked food
	Show status effects for Love Potion, carried water, anal beads from punishment, gassing garden spot, moriya date indicator, amount of people at the location (moved from translated branch)
	
@情事発覚.ERB
	Show character portrait during the first meeting <- disabled, now implemented natively
	
@USERCOM_コマンド表示処理.ERB
	Highlight Souvenir Shop button when the trade flag is on
	
@MAP_COMM
	Alter location names when you live there for consistency, alter room names when lodgers move in
	Hakurei Shrine - Three Fairies, Yumemi / Myouren Temple, Miko / Forest of Magic - Marisa, Ellen / Mountain Top, Tenshi / Underworld, Satori / Moon, Doremy
	in str.erb translated branch - Kasen, Aki, Watatsuki
	
@DAIRY_EV4 MONOOMOI.ERB
	Show character's face
	
@COMF410 掃除.ERB
	Minor line to show time passage
	
@DISHDATA.ERB
	Shows whose special dish it is
	
@QoL_ShowRelation.ERB, @SHOW_RELATION.ERB, @LIST.ERB
	Replace original list, sort it in ascending/descending order from highest to lowest affinity and vice versa (descending by default)
	Can be switched back and forth with a button
	
@MOBGIRL_GENERATOR.ERB
	Hide gained experience for newly generated random girls
	
@QoL_DetailedInfo.ERB, @PRINT_STATE2.ERB, @能力表示.ERB, everywhere QoL_DetailedInfo is used
	Replaced and expanded a lot of info parts
	@QoL_ChildStatus Show detailed info about child's current growth stage, show correct age and time since independence
	@QoL_WakingTimes Additionally show waking hours for friendly characters
	@Qol_Info_House More clean version of showing character's home location, replaces section in @PRINT_STATE2.ERB <- Currently only to show player's home location
	@Qol_Info_Dialogue Show currently used dialogue for characters under their names on ability screen (能力表示.ERB)
	@Qol_Info_Dates Show significant time dates with other characters - from LIG
	@Qol_Info_Body Show various minor first times from all over the place - from LIG
	@Qol_Info_Penis Expanded penis description - from LIG (unimplemented)
	Qol_Info_AverageFavor - Show average favor on achievement page and personal page (by AK Spectre)
	COMF444 女の子を物色.ERB - fixes incorrect check for first meeting time with randos
	Qol_Info_ChildList - currently disabled, a bigger list for character's children, currently hard-limited by 10, consider using when the limit is lifted
	Added counters for some things, only counts things that happened via actions outside of events
	
@外出先から帰宅.ERB, @QoL_DateEndConfirm
	Ask for confirmation when going home/finishing date.
	
@COMF604 散策する.ERB
	Ask if you want to visit Love Hotel with unconsenting character
	
@Qol_DishTaste, @COMF413 料理を作る.ERB
	Search dishes by its base taste at the cooking screen
	
@QoL_Stall, @COMF447 露店を開く.ERB
	Highlight items that sell the best when you have sufficient speech + knowledge (because that's used for haggling)
	Other useful info added
	
@Qol_GiftReview, @Qol_GiftShowTaste, @Qol_GiftData, COMF413 料理を作る.ERB, COMF626 土産屋.ERB
	With knowledge divided by cost (sub 10k 3 knowledge, sub 50k 4 knowledge and above 5-6), you can visually identify items and get a clue for their preference, approximate score based on knowledge
	When choosing a gift, show its name and its preferences (when you can), confirm to buy, approximate score next to the name in the list (based on price, if requirements met most accurate, go up to 2 when inaccurate, then none)
	COMF626 土産屋.ERB - show time spent choosing the gift
	
QoL_Misc.ERB, SOURCE.ERB
	Show spent TSP in source, using hack because it's not handled via DOWNBASE
	
@COMMON.ERB
	Highlight DRNK in red when Turmeric Drink was used and active

@情事発覚.ERB
	Show if characters are working when you see them
	
@QoL_HighlightRequestChara
	Highlight characters with requests on interaction screen.
	>If a girl has a request for you her name gets a green highlight at the top, under the TSP gauge
	Low priority, other highlights will override this one
	
外出先から帰宅.ERB
	Show when characters are available if you can't date them at the moment
	Show the amount of TSP needed to use TSP travel
	Show how much STA damage you took from the wind
	
BASE自然変動.ERB
	Show how much STA damage you took from the weather
	
SHOP.ERB, INFO.ERB
	Show current year + current new game playthrough (NG+ counter)
	
QoL_BypassCheck(ARG), CCOMF41_正常位Ｖおねだり, CCOMF43_後背位Vおねだり, CCOMF44_後背位Ａおねだり, CCOMF80_正常位される, CCOMF83_後背位される, CCOMF85_騎乗位, CCOMF87_騎乗位Ａ
	Extended stable check bypass to COUNTER actions with them having the initiative
	
DAIRY_EV5 OPPAI.ERB
	Added futa god hint;
	
COMF449 虫捕り.ERB
	Added paging to the list of caught bugs from the bug page
	
OGAMITAOSHI.ERB
	Hint for raw sex persuasion attempts + visible counter
	
酒関連.ERB
	Change IS_ALC check to reduce lags, store all booze name first in an array strBooze when the day starts and use it to quickly find items
	
ANOTHER_TALK.ERB, COMF450 酒虫の様子を見る
	Show brewing stage with high education, add tips to menus, add list of ingredients
	Show currently working 2hus and 2hus doing idle activity (might be spammy)
	Show when radio is active
	Show descriptors when characters are sweating due to hot weather to avoid confusion
	
OPTION.ERB, LIST.ERB, USERCOM.ERB, QoL_Misc.ERH
	Store previous value of the image flag before it's turned off, and restore its value when enabled.
	
SHOP.ERB
	Add quick-access calendar button to main menu
	
USERCOM_コマンド表示処理.ERB
	Gray out conversation action when you're out of topics to discuss (after skill check is passed)
	
BEFORETRAIN.ERB
	Highlight child's birthday line
	
COMF697 部屋を訪ねる.ERB, FUNC_IRAI.ERB, CTRL_IRAI.ERB
	Add portraits to visit home and for completing requests at a character's home place (delivery, etc)
	Add duel for allowed list of requests that can be completed at a character's home place
	More robust checks for easier completion of requests at a character's home place when they're unavailable (delivering a letter, returning lost item, duel), highlight their home in yellow if the request applies to them
	COMF367 依頼実行 - make so that complete the request button doesn't appear when at someone's home place and they're away (must go to their room)
	
OTHERREGION.ERB
	Easy switch between TSP movement and normal when moving between maps
	
@QoL_UnlockExtraTraitsInfo, PRINT_STATE, 能力表示.ERB
	Show info on all unlockable traits
	
@QoL_Misc, @EVENTTRAIN
	Added notification for Christmas Gift
	
@LIST.ERB, _Design.ERB, QoL_Misc.ERB, SOURCE.ERB
	Show progress bar when acquiring skill experience
	
@QoL_AllItemSort, @PRINT_STATE.ERB
	Sort items by categories on the item screen, search items by name
	
@COMF413 料理を作る.ERB
	Option to exclude cooking assistant
	
@COMMON.ERB
	Color code gauge labels when close to exhaustion
	
CHARA_DIARY.ERB, COMF406 日記を読む.ERB
	Improve main menu, add diary reset option
	
LIST.ERB, QoL_Misc.ERB
	Adjusted progress bars to show progress to next rank
	
SHOP.ERB
	Uncommented child list to use our version of the list
	Improved special dishes list, show the amount of learned recipes/total recipes, add search taste search

COMF351 連れ出す.ERB
	Added an option to exclude an already accompanied character from being led

QoL_Misc.ERB @QOL_SHOW_GATHERING_ITEM(PLACE), COMF445 採集する.ERB
	Expanded function to show how much of each material the player already carries
	Moved to its own function for maintainability
	
DRAW_MAP.ERB
	See rooms that are already spotless
	
SHOP_住環境設定.ERB
	Cleaner rendering of time slept
	An option to quit out without changing sleeping time;
	
集合.ERB
	Highlight the "Execute Gathering" button when it is available;

@CUSTOM_OPTION_7, @CUSTOM_OPTION_RESULT_7, @SET_MAP_WEATHER_BGCOLOR
	Add toggle for weather-dependent background color (default off)
	Disabled due to the original game adding the same option

@QOL_PRINT_NPC_ACTIVITIES, @QOL_PRINT_NPC_ACTIVITY, @JOB_DEPICTION_STR, @ARRAY_EXISTS_ALL, @MESSAGE_TALK
	Place characters engaging in the same job/activity on the same line, instead of generating a single line per character
	Add unique group names for specific sets of characters