You can also replace common or shared attributes between your configs using env files: https://docs.docker.com/compose/environment-variables/set-environment-variables/#use-the-env_file-attribute

Things I put there: UIDs, GIDs, TZ, shared mount paths, etc.

No, that is counter intuitive. It may appear more expensive at first, but on the long run it is a lot more cheaper. It avoid vendor lock-in, recurring increase of dev costs and licensing and lots of other plagues of closed proprietary development like blackbox development and justification of hidden complexity as a driving factor on costs. I worked with legacy closed proprietary sw development and lock-in combined with legacy complexity made man-hour costs exorbitant. These are partially solved by open-sourcing, as kicking out a team and putting a new one is easier, but most importantly transparency as a driving factor on quality of development.

plex_debrid looks the way to go with. I was put off it because its name and I use jellyfin. Reading more closely it works with jellyfin, so cutting off the middleman (radarr) seems like a very good solution!

Is there anything special to know about it before trying myself? Any issues or roadblocks you had when setting this up?

Thanks for the answer!