It may be possible to create a UI using a monitoring program like Zabbix.

You could create a custom dashboard that displays all the stats that they need to see.

This of course would be for viewing only, not controlling the schedules, retention etc

I've never done it so I can't say for certain.

I typically buy purpose built routers which advertise routing speed benchmarks

Ubuntu 22.04 base with a Plex docker container. ZFS as the file system on my host

Same

Linux Mint is what I use and have no issues with my 3070.

Chimera OS might be something you can look into however I have not used it

Pop OS is also great for nvidia support

It's using the Duckduckgo app

Can you send you docker-compose file?