I tried few version of Fedora on Librem5 non of them worked including the ostree silverblue fedora, could be I have an older prerelease version, so I will wait for the next release before christmas and test it.
I removed the PureOS from my librem5 and I am using e OS https://e.foundation/ (android clone),
it is more stable and works better, PureOS maybe be ok for PC for phone it is not at least in EUROPE,
the phones drop 3-5 minutes, SMS doesn’t work and software and few key apps are not stable, but it might be cause I have pre release version or the PureOS is not yet in final version or the apps are not tested for europe, europe and north america use different mobile phone infrastructure could be it.
“purism apps should be flatpaked,” I believe not since PureOS the OS of purism on Librem5 is based on Debian I believe the apps may be snaps but not flatpak as far as I am aware,
not sure what do you mean, but yeah if you want to say PureOS works ok in VM yeah I believe the same before I got the Librem5, but on the phone it is a different story and many of the phone basic services like phone calls and sms don’t work (could be just an issue in europe) and I was not able to get 4G or 5G (my city has 5G in germany already) only 3G with about 1mbps (could be just europe).
I personally would prefer Fedora based, not debian based OS like PureOS, I use RHEF for ALL work and home (CentOS+Fedora Workstation + Fedora Silberblue for everything even games) and migrated my NAS to CentOS and making a MiniPC router based on Silberblue to replace my OpenWRT.