So PeerTube is another open source project providing a video streaming and video on-demand platform with similarities to youtube but features peer-to-peer data sharing for playback and activity pub social networking protocol.

PT needs lots of video transcoding to host videos and it has a tool called a "runner" which you can install on other hosts to farm out transcoding duties.

Rather than reinventing the wheel, perhaps PhotoPrism can utilise this existing tool to have transcoding duties running remotely on a peertube runner - that may even be used by multiple instances of photoprism front end - or even shared by another PeerTube frontend. It would be a huge infrastructure boon for having a large set of PhotoPrism instances deployed for a single organisation.

Here's more information about the runner tool itself.
https://docs.joinpeertube.org/maintain/tools#peertube-runner

And here's some information on how PT manages it from the web app (admin)
https://docs.joinpeertube.org/admin/remote-runners