The only time I haven’t been able to do something was with a VPN client that came as a self-executing tarball. Because it tries to mess with Network Manager on the fly, it doesn’t work correctly.
So there’s a handful of weird edge cases, but I agree that the majority can be solved with podman or distrobox.
Spiral is Debian. Like Endeavor, it’s primarily a way to install Debian with a few sane defaults and graphical choosers to install other software. Otherwise, it’s just Debian.
Try it in a VM. I was surprised how fast it was even in that limited environment, and if not for the fact that I want/need a newer kernel, I might have chosen that one.
But otherwise, sounds like you’ve kind of already chosen.