I would rather keep the base specification of lightning simpler, as that makes it more likely for more implementations in the future. Having it baked in the base spec also makes it hard to expand on it incrementally.

BOLT12 and LNURL are very similar in nature, both boil down to a communications layer for negotiating invoice creation. Bolt 12 comes with stronger guarantees on privacy, but we can probably achieve decent privacy with nostr with clever tricks.