This public beta is only for macOS 12 users. It is to work around an apparent bug in macOS 12 that interacted with a recent feature of Hook, causing a spinning beachball.
Extremely few users have reported this issue. If you are not running macOS 12 you do not need it. Or if Hook is working fine for you on macOS 12, you don’t need it.
background: we’ve noticed a couple of bugs with macOS 12 . We’ve worked around the one that affected PDFpenPro. And we’re working around the one alluded to above. We’ll have more info to share later.