I'd say HS2 toes exactly the right line in terms of intermediate stations, only if it only goes ass far as Birmingham their usefulness will be halved! I can't for the life of me fathom why so much money and time was spend trying to create NPR as a way to piggyback off HS2 into Manchester to get a better BCR. With a base of 5 400m trains per hour, and potential to go to 8tph (Original 4 platform terminus) the case always stacked up. If it didn't, it wouldn't have been proposed.
Also anecdotally, whilst Crewe wouldn't be an "HS2 Mainline Station" per-se, it would effectively serve as a major interchange for North Wales & Chester which would get much better journey times to Birmingham/London by changing there rather than going on a direct WCML service.
Manchester Airport station perfectly captures the lucrative South Manchester/North Cheshire to London market which represents about 1/3 of Manchester-London flows. Forget messing around trying to bolt NPR on, just go back to the original HS2 only plan and build the thing. The benefits will tell the story for themselves!