I think that it would be useful to include a method every variable of a particular category from a specified actor.
It will be a node with an actor input and a category drop-down selection that adapts to the Actor attached to the input.
The node will take the actor reference, get its class and derive a list of variables that are of the selected category. Changing the category will change the list of output nodes.
I believe that this can help in cases such as the implementation of an Actor that serves as a container for global variables.
For example; another Actor referring to the container Actor could use the aforementioned node to get a list of boolean variables of a category that is relevant.
Due to the necessity of casting, I am not sure if such a node will be easy to implement.Mockup: