I heard that cashapp has been working on lightning address for awhile so I've been checking these endpoints every now and then. They've been returning nothing until recently where now they are returning the full valid LUD06 object along with the nip57 "allowsNostr" and "nostrPubkey" properties. (So Zaps are on the table through cashapp??)
You can find your endpoint by replacing "jack" in the url with your cashtag.
The callbacks return unauthorized when I try to hit them for an invoice which makes me wonder if cashapp is setting up LUD18 for auth/compliance on these endpoints?
Anyway found this interesting, thought I would share, cheers!