Woa, is this a future RF 400 f2.8, or the EF 400 f2.8 III for $12K one?
I don't happen to use the Mac for games (funny, I'm a retired "game designer & programmer" who's tired of playing video games). Photo editing (PL4) is the most taxing thing I do. Pano stitching (PTGui) or Affinity Pro edits of super large files also done. Maybe I'll get into R5 video editing, but I've not done that before. So I don't know if "more cores" will make a big difference to me or not. I would probably max out the fast ram as well as the ssd ram which I know would cost a lot. I would like to have a newer & bigger display (my 2nd display is an old 27" Apple Thunderbolt display). Is it an Apple 6k screen you're considering?
What is in the M1 MBP that you want that the M1 MBA doesn't have?