I've heard Hidamari ga Kikoeru is supposed to be really good, not 100% if it is a slow-burn tho ( https://www.mangago.zone/read-manga/hidamari_ga_kikoeru/ )
Candy Color Paradox is one I have written down as a slow-burn and i'm planning to read it really soon, but it is supposedly really good ( https://www.mangago.zone/read-manga/ameiro_paradox/ )
Rainbow city (SA in chap 3, best to skip)
Little mushroom
Breaking through the clouds 2: swallow the sea
any bl manhua but fr i recommend these
i have to be a great villain
19 days
mo dao zu shi
here u are
semantic error
my guildmate next door
Sangyang:The Wanderer
https://www.mangago.zone/read-manga/sangyang_the_wanderer/
Honbul : Flame of the Soul
https://www.mangago.zone/read-manga/soul_fire/
SLOW BURN BLS PLEASEEEEEEEEE