Enabling an Annoyances list in ublock origin prevents some of these from dicking up, thankfully.

I followed this guide and it works great! https://www.gamespot.com/articles/how-to-play-diablo-4-on-steam-deck/1100-6514752/

I'd think following a guide for Diablo 4 to get bnet installed and then install D2 resurrected should work.