Howdy. In building a complex models, I have certain GEO object nodes that I would like to be able to control the display of, specifically, the blue tab on the node. I have a null set up where all of my control parameters are stored for different channels but is it possible to make a check box in my control null, that directly turns on the Display or visibility of another Object node?

you can add a toggle to the control null
then in it's Callback Script put whatever code you need.