Yes, I have a 210M-X and my unlocked arm is set to 45 degrees. This is for a sandwich of two 4-ply boards where the photo is on the primary board, and a secondary covering board is on top without a classic cover sheet over the photo.
For print flattening I use the same setup, where the photo is sandwiched between two 4-ply boards, but without the adhesive sheet. I tried flattening once with the smooth cover sheet over the photo, but it had the effect of physically flattening the unferrotyped glossy texture, making it looked... smeared... for want of a better term.
(Note that I also use a non-hardening print fixer, which may have left the surface texture more delicate than it may have been with a hardening formula.)
Ken