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.
Discussion
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Many versions out of date based on the years.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 🤦♂️