I understand you want to use NINA, tho you also mentioned SGP.

I mentioned it as one of the three tools documented as required.

Fwiw I use APPM with SGP and ASTAP, and it seems to work fine.
It takes about 35 minutes to run a 71 (iirc) point model (which i
run during astronomical twilight before it’s really dark).

Good to know.

I suppose this would require switching to SGP for APPM, then shutting
that down and running the imaging session with NINA.

Exactly. I do that with TSX (shutting down the camera side) when I switch to NINA after running tPoint. I'm assuming APPM is similar, just looking for what the most straightforward solution will be for just that aspect.

Unless I get lucky and timing works out!