I don't see any reference to nostr at all on the site

if it doesn't support nip-89 there is no difference in writing a long URL or a short URL wrt to not explicitly deciding to what client I'm linking

to be clear: I don't care about the length of the URL

I just care that if you prefer using blogstack and I prefer using nostr.com to read NIP-23s, when I link to it I can impose my view of what client you should use or not. With NIP-89 I don't impose my view on you, you just read what I linked to with whatever client you like.