Further on the concept of diagnostic and troubleshooting steps being disruptive—for consistent hanging (or crashing) it’s almost always necessary to disrupt things for a bit, because Scrivener itself is rock solid stable in an expected configuration outside of a few known rarer issues that do not match what you describe. The implication is that the context needs to be tested more than Scrivener, and that can mean shutting off all of your normal programs for a while, gradually bringing them back, booting into safe mode, and other tests. None of that is meant to imply you should forevermore work in safe mode for example (yikes), but it’s how we figure out what is actually messed up, so that the source of the problem can be surgically removed (or updated, as the case may be) and you can otherwise go back to doing everything as you normally do.
The advice in this post is a good checklist of things to look for when running into issues. This will be particularly true if you used Apple’s “user folder migration” utility to carry over everything to the new Mac. That can bring old problems over, and old plug-ins and such that no longer work and are now just causing other programs to crash.