that is weird behavior indeed,
I’m currently doing testing on Mainline 5.12 v210520, everything works from sound to the wifi, keyboard and mouse. I suggest using XFCE, its much more lightweight
I’d suggest doing a backup from the eMMC and trying out Mainline server v210520 and then installing Xfce on top of it, mainline has a lot of room for optimization like extensive overclocking (I’m currently working on it) and GPU optimizations (ask @clort76 for more info on setting up Wayfire ) these can make the system even more responsive and faster,
so I’d suggest you to do some testing by yourself before you select an optimal setup for your use case,
please test whatever is optimal and take notes, helps you and others
best of luck!