mudmask - Glad you found a workaround. Unfortunately, fixing the point issue would make it so all the sprites being moved around to animate the character would lag behind a tick if you pinned the character to a sprite using the pin behavior or something similar. It seems like the it has to be one or the other, since the only choices are to animate the character and update the point values at the beginning or end of a tick (before or after all events), and either choice causes one of those two issues.
I would keep an eye out on the main Spriter thread, however, as this is something that might be streamlined with sub-entities. At the moment, importing sub-entities are a little cumbersome to import, but I have an idea I'm going to try to add in the next Spriter update that will make it a lot easier. Assuming you had the top half of the character as a sub-entity attached to the bottom half, you could just call an override action to change animations on the top half.
Edit: As another user is having a similar issue, I will see about having an action that will let you attach a c2 object to an image point, to let it manage this for you. If it works out well, it will be an upcoming plugin update.