I think I wouldn't mind there being some generic Acrobatics rider action to avoid reactions from movement, with Kip Up and Mobility being the upgraded versions that just work automatically/faster.
I agree. A middle ground between "standing up costs an action AND triggers reactive strike" and "standing up is free and does not trigger anything" would be nice. Kip Up being amazing and one of very few counters to prone is a big part of why I'm addicted to the Acrobat archetype.