> I wonder if I would get used to using a single key for each app versus Alt-tabbing. I believe this is the main cause of my left wrist pain.

I use that kind of setup (kinda) in i3, it is great. It's not one app per key, but one keybind per virtual desktop but I have i3 set up that apps autostart and gets placed always on same desktop

So going to IDE is always caps+4 (I rebounded caps to act as modifier), mail client is caps+F2 etc.

Then few keybinds to move stuff around for those 2% of cases where I need apps on different desktops than usual.