Hi! I've tried the new features we discussed from 2.3 and I think that you seemed to have lost focus in the core functionality of your plugin, feeling like it lost its simplicity, the dynamic attachments are mixed along with the original contents and the UI ended up cluttered and less intuitive.
I can suggest providing two tabs, one for standard behavior and a second tab for dynamic attachments and actions, right now I'm not sure what to think about there's too many buttons spread around and I'm not sure which one is the actual button for grabbing, I assume that I must first have the attachment point selected to later trigger it from a button (can they be triggered through the timeline? If so, how?)
So far I haven't tested anything else, that's all I had to say!