I've defaulted to installing as many apps as I can thru flatpak. Nixpkgs is just for system level stuff. Otherwise, you gotta jump through hoops. Plus, commonly updating apps thru nix is a bitch.
Discussion
Interesting. Flatpack was annoying as hell in Ubuntu. I hated having apps spread across multiple package managers. Maybe worth a revisit in a different context. Still 2 package managers to update.
Agreed, managing multiple systems is annoying. Snap sucks though, so I've completely replaced my snaps with flatpak and I'm very happy with it. Make sure you also install Flatseal, since it gives you a clean gui to handle the permissions of individual flatpaks.
No onlykey flatpak, so I need to keep at it anyway.
I see on github somebody built a flatpak, but it hasn't been updated in quite a bit. https://github.com/trustcrypto/OnlyKey-App/issues/105
Many versions out of date based on the years. It looks like they also offer a snap 🤦♂️