I was going to say that the DANE PGPKEY stuff was another interesting use case for DANE, but on doing a search for clients who supported it, it seems the answer

I was going to say that the DANE PGPKEY stuff was another interesting use case for DANE, but on doing a search for clients who supported it, it seems the answer there has just been to use a .well-known https: url instead. If even the PGP enthusiasts can't be bothered to use the approach, it must be well and truly dead.