https://www.mangago.zone/read-manga/tu_quoque/
Like you said, you've probably already read this lol
this one isn't completely wholesome but it's tagged as slow born nd isnt too long (nd not shounen ai)
https://www.mangago.zone/read-manga/blue_sky_complex/
this one is slow burn nd not shounen ai, but its long
https://www.mangago.zone/read-manga/green_apple_paradise/
I hope you find some titles you haven't read and enjoy them. I personally love all 9f these.
https://www.mangago.zone/read-manga/almost_paradise/
https://www.mangago.zone/read-manga/snow_fairy/
https://www.mangago.zone/read-manga/metro_dog/
https://www.mangago.zone/read-manga/ikumen_after/
https://www.mangago.zone/read-manga/shitasaki_ni_yoake_no_aji/
https://www.mangago.zone/read-manga/under_my_skin/
https://www.mangago.zone/read-manga/friend_line/
https://www.mangago.zone/read-manga/castle_mango/
https://www.mangago.zone/read-manga/don_t_call_me_daddy/
https://www.mangago.zone/read-manga/hana_ni_kuchizuke/
howsntly some of these are not slow burn or even shounen ai but i enjoyed a lot sooooo https://www.mangago.zone/read-manga/pink_heart_jam/
https://www.mangago.zone/read-manga/fools/
https://www.mangago.zone/read-manga/the_best_smell/
https://www.mangago.zone/read-manga/heesu_in_class_2/
https://www.mangago.zone/read-manga/cut_over_criteria/
https://www.mangago.zone/read-manga/snail_pond_robber/
https://www.mangago.zone/read-manga/king_s_maker/
https://www.mangago.zone/read-manga/hyung_you_re_my_idol/
https://www.mangago.zone/read-manga/unintentional_love_story/
https://www.mangago.zone/read-manga/green_apple_paradise/
can anyone recommend a really wholesome BL manga (preferably) that has a slow burn but not super long and not a shounen ai
please note that i read a lot so i already know most of the popular ones