Yep, that’s it!
My one suggestion for those reading this, please run the following command first:
ha resolution info
I put in some checks which test user-provided DNS servers to ensure they don’t have issues. The check for the situation I described here in particular is not obvious. It’s entirely possible that your local DNS server has this issue and you’ve never noticed since it only affects musl systems.
So please run that command and make sure no dns server issues are in the list. If there are none then feel free to disable the fallback.
If there are then I would strongly advise fixing those first otherwise you may have unexpected issues. Particularly around updating and installing containers since queries for github.com and ghcr.io resolve on A queries but not AAAA. If you do have the ipv6 issue I linked and you disable the fallback anyway you likely will see all your HA containers suddenly start to think github.com and ghcr.io don’t exist and hit a lot of problems.