I just came here to say exactly the same thing. Tapes for the long term, but you also have to take reaaaaaly good care of how they’re stored ie. don’t store them under the kitchen sink in your bathroom

if you use Let’s Encrypt (ACME protocol) AFAIK you can find all domains registered in a directory that even has a search, no matter if it’s wildcard or not.

It was something like this https://crt.sh/ but can’t find the site exactly anymore

LE: you can also find some here https://search.censys.io/