Neat project!
While this might not solve all of your use cases, did you consider a tool like mise?
Theres a number of other options out there such as asdf-vm and others who's names I can't recall. I recently moved from asdf to miss but its a great way to install things on different machines and track it with your dotfiles, or any other repo you want to use. Mise has tons of configuration options for allowing overrides and local machine specific versions.
It won't tie into apt for your upgrades but you could just alias your apt update to include && mise up.
This bigly. Everyone innately deserves respect. You can absolutely lose it for being a wanker.
"Respect is earned" needs to die in a fire.