Using JAL F lounge on separate tickets after arriving in First?

I’ve got an int’l connection at HND on separate tickets. Arriving in JAL First, but my onward options are two backup economy awards on ANA and JAL (Aeroplan and Alaska). I’ll probably take the ANA one since it’s easier to cancel the Alaska/JAL booking.

I’d still like to use the JAL F lounge, either off the inbound F or my oneworld Emerald status. Just not sure if separate tickets make this messy or if accessing off the arriving F segment is fine.