yeah, i can't think of anything practical off the top of my head. but there's no reason i can see why lightning terminals could not send the invoices over NFC. hard agree. someone needs to do it.
i do think a secondary feature that would be useful is that when the NFC sends the invoice, it could also negotiate a bluetooth link so the user's phone doesn't need internet access to dispatch the payment to their lightning node or custodian or LSP.