I'm not even sure how to briefly summarize this so I'm sorry for the coming logorrhea. I'd like to have basically all conceivable host names quietly ignored, with the exception of two: home.mydomain.com should point to a dynamic DNS (this is my house server, so DDNS is needed, currently *.mydomain.com points over here) and aws.mydomain.com which has a static IP sitting in the AWS datacenter somewhere over by Podunk. I've got the aws host set up, but I can't for the life of me figure out how to only get a single host name to resolve to my DDNS address.

You can disable wildcard alias option for mydomain.com in the control panel. Then you can create a sub domain name home.mydomain.com in "Aliases" section to point to your home server.

If you are using Dynu IP Update Client, you can assign home.mydomain.com a Location name in the "Aliases" section and use that Location name in the IP Update Client to update only home.mydomain.com. That way, only home.mydomain.com maps to your dynamic IP.

Beautiful, thank you!