I personally use piCorePlayer on a raspberry pi which is basically burn an SD card which gives you a squeezebox (basically a client) there’s a couple more steps to get lms running on top of that but the instructions are pretty good: https://docs.picoreplayer.org/how-to/install_lms/

Official docker image seems to be here https://hub.docker.com/r/lmscommunity/logitechmediaserver

You’ll want to install the “material skin” too if you do get it running, it’s a pretty modern front end:

https://github.com/CDrummond/lms-material

Official forum is packed with info too:

https://forums.slimdevices.com/

Yeah! The squeezebox software is still out there too, it’s a sudo apt-get get away in something like it Ubuntu and just works (though does commandeer the audio on any pc you do that on by default)

Logitech Media Server (LMS)/slimserver may tick a lot of your Roon requirements.

Not to mention how long it takes a big org to migrate, even between versions of rhel. I’ve seen 6 -> 7 migrations happen inside the last month.