Current system doesn’t allow any control over the order of variable categories - in Class Defaults tab, it appears like they’re ordered randomly.
This is the original AnswerHub post: How to reorder variable Categories in Class Defaults? - UE4 AnswerHub
Seems like many people want this, so I’ve decided to make a feature request.
This would be very useful not only for our private projects, but also for end-users of our Marketplace tools.