I haven't read too many but here are some:

Maybe by Jesuscheese
Platonic Shua Centric
https://archiveofourown.org/works/21911212

I'd fall anywhere with you (I'm by your side) pocketpastel
SeokShua
https://archiveofourown.org/works/23012407

Winning (Against) Yoon Jeonghan stilljunhui (acyria)
ShuaHan
https://archiveofourown.org/works/10936911

Festively Yours thanku4urlove
SoonShua
https://archiveofourown.org/works/29035605

Poison Or Medicine by Anonymous_Introvert78, MinYun
This is a ChulHan fic but romance isn't the main thing and Shua has a main role and then even more so in the 2nd part of the series
https://archiveofourown.org/works/22637218