MXTX mains by ascending order of how much fun they'd have if their love interest shrank to pocket size:
6 Lan Wangji -- this poses a significant impediment to his sex life and also is nearly as stressful as wei ying running around in paper man form, but much less easily reversed.
5 Luo Binghe -- look, tiny shizun is cute, but the novelty is going to wear off quick and then what? this shizun has to fly up on a tiny sword to even pat Luo Binghe's head, his lap is not big enough for Binghe to lie on, it's just not sustainable.
4 Hua Cheng -- theoretically he's not against this it's just that xie lian would manage to be the most stressful unholy terror if he was mouse-sized, I think.
3 Shen Qingqiu -- actually he loves this, look at the itty-bitty binghe! but his ability to enjoy it is dampened by luo binghe's genuine and obvious misery with the situation. binghe worked so hard to get taller than shizun and now it's all ruined! again!
2 Xie Lian -- same as shen qingqiu actually he thinks smol san lang is very cute, and hua cheng is better at handling this development than luo binghe. unfortunately it does kind of remind them of when hua cheng was a helpless ghost light and xie lian was being tortured.
1 Wei Wuxian -- he's making lan zhan a tiny guqin.