bolt12 specifies, for Offers, a TLV of type: 22, value: 32 byte offer_issuer_id (i.e. a pubkey)
https://github.com/lightning/bolts/blob/master/12-offer-encoding.md
Discussion
This is very much a misread of the spec. nostr:note1ehvw9rucz7jclm6r2pfn93wacuerqrl8l6e7yy7968upws5tr27qpryfwp
I appreciate the correction you offer in the post I reply to below, and I think this is a good recommendation: for good privacy, don't reuse a bolt12 or any other payment string across multiple services. Instead, make a new payment string for each service you use.