Hey Dave!
Yes. 
So we have multiple categories which are available to all users. There the option that only the user who submitted the topic and admins/moderators can choose a solution is perfect.
But we also have categories which are only available to a specific group. (Our clients in our case.) The group is usually entrusted that they all have the same rights. Everyone can stand in for anyone else. So here it would be great, if anyone in that group could select a solution.
Using the current global setting “Accept all solutions allowed groups” would be great for the latter categories, but would break the categories for all users. Here the “Accept all solutions allowed groups” per category would come in handy. One option to override is already available in the category settings, this one I would expect there as well.