Thanks for all these great suggestions! I had heard the name LoupeDeck, but had no idea what it was. I happen to have a few split programmable keyboards and a pile of components that I might be able to frankenstein together into a home-brew version.
KDE Connect also sounds super useful, I will investigate that as well.
I actually have a standing desk at work, I ought to use that more consistently. That might make sitting in the evenings more bearable.