I agree, that would probably not work really well with the way Nostr works. A NIP to set your payment address would be nice. I'd prefer to set it to either my Bitcoin on-chain address or e.g. an encoded Bolt12 offer but that's just my personal preference
Discussion
On that note, I haven't played too much around with Bolt 12 yet, just read a bit about it. Seems to fit this purpose, that's why I mention it.