Was running the same setup pretty much, I really miss it. Was running arch with an 8c/16t cpu, with 32GB ram, a 2070 Super (for passthrough), and a cheap GT710 (for i3wm on host). I've heard of Looking Glass and SCREAM but never tried it, instead I would switch inputs on my primary monitor and keep i3 on my secondary. Just used an Elgato Stream deck with Streamdeck_ui and would set attach and detach commands for peripherals, and others like power/pause.
Ended up helping someone troubleshoot their PC, which turned out to be a dead GPU, and I gave them the 710 as a better then nothing card. Was still able to play a lot of my games native or via proton on the 2070, but some new games had performance/compatibilty issues and I couldn't use RTX. Ended up installing Windows over my Arch to play them, you know just till I could get a new host GPU.
Now I have a GPU for the host again, but I'm using Microsoft Storage Spaces for my RAID 10; and, being lazy as I am, I just keep putting off copying all of that to spare drives and rebuilding with mdadm. Plus the fear of losing terabytes of data during migration is intimidating.