Well, it’s a pity … Monterey is a game stopper.
We are going to look into bumping the version requirement down one to Monterey. It may not be possible with the system APIs that we want to use. That said, eventually we will need to move forward to a higher OS requirement, but just like we do for Photo Mechanic 5 and 6, we'll do our best to offer downloads of older builds for folks who want to stay on older OS's.