Not clear if OP is flying premium cabins (in which case, status won't matter that much), or coach. Further, sounds like OP intends to keep earning Plat on DL by spending $125K+ annually on an Amex Reserve. Trying to leverage benefits from status in one program (like preferred seats, priority check-in/boarding, lounge access), while crediting flights to a different one, is often challenging. And if you are flying coach, we aren't talking about that many points any way. I don't really see it as worth the effort to split points earn between two programs in the case of OP flying coach (and not trying to earn FB status). It might be worth the effort if OP flies enough to earn FB Gold status or higher (and doesn't have to rely on DL status for benefits).