There are a couple ways to achieve this on Fly short of Fly letting orgs muck with internal DNS zones.
- Pinning a VM to a host (by mounting a volume) so its
alloc-iddoesn’t change as often. - If
<appname>only ever deploys one VM per region, then<region>.<appname>.internalis as good as aCNAME(alias) to that singular VM.