Category limits with parents categories on V2

It seems as though category limits are not being observed correctly on V2 if there is a parent/child category structure.

For example, on a certain package I allow a user to choose a parent category and one child category. This works fine on V1 using Ajax-chained. It stops the user from choosing two child categories as they must select the parent first.

On V2 a user can choose 2 child categories and because of this won’t then appear in the parent category.

Is Ajax-chained likely to be added for v2 anytime soon? If not I’d appreciate your thoughts on how to enforce users to choose the parent category.