The verification for NIP-05 is inherently both. The DNS is a preliminary requirement to host the txt file in the first place. Unless I'm misunderstanding what you're saying in the original post, this feature is already there.
Discussion
Yes however you'd need a web server to host the JSON verification file to my knowledge. I have a domain but not a web server, I would prefer if there was a DNS TXT record as an alternative so you don't need a web server if that makes sense.
Ahh I see what you mean. Yeah, that would be a nice feature.