

To further simplify.
For step 1+2 , the router might have a built in DNS resolver which would eliminate the need to maintain another container or service.
For step 5, depending in the router software, with a single target (e.g. a nas running docker services) you might also be able to add a wildcard rule to catch any query for *.local.domain.com to resolve to that machine. This would simplify adding things in the future as the only thing remaining would be the caddy config.

Also, depending on the location they can be unreliable (US higher end models at least).
A coworker bought one with 60k miles for about 30k (included 100k extended warranty). He has a Toyota now. I believe the beamer was considered a total dud around 110k due to electrical issues.