I just set it up. Wasn't that difficult:

1. Added a new postgres db and user 2. Added a new dns name 3. Added a new cert for the new dns name 4. Added a new vhost to nginx to proxy to a new port using the new dns name and cert 5. Added a simple docker-compose to my config 6. Added a snippet to my .well-known/matrix/client

Don't imagine it will take much maintenance. Container will be updated along with the rest of my containers, and the existence of the service doesn't change anything for any existing clients that don't support sliding sync.