I use fastmail's * alias against a custom domain, to achieve a similar thing. It forwards mail at any address to my normal email, then I just pick a name on signup, ie. hn@emaildomain.com.

I have registered a domain just for the purpose which doesn't have my name in it or host any websites or anything else which can be used to leak my identity with a whois privacy guard service.

It has the dual advantages of being guessable by me if something goes tits up with my self-hosted bitwarden, and I can eyeball who has leaked my email address on incoming spam.