Been using Fedora Ublue for a while now. It really just works and is up to date. Even nvidia drivers and secure boot works immediately. The updates also happen automatically and are actually just immages being downloaded and switched to by a reboot. And of courss I have a distrobox with arch for the aur
is it accurate to say that's like an alternative package manager?
Yes, that is correct. It only hosts open source apps and also supports adding extra repositories. The fastest way to get updates would be to use the IzzyOnDroid repository. I can recommend the Droid-ify app as it supports automatic updates for apps. It also comes with the IzzyOnDroid repository enabled by default