66 holes under center dash - what for besides deluxe heater mount?

[msg]

Im running into trouble with a deluxe heat control assembly and I might need to create a 2nd brace on the opposite side of the unit to make the unit sit flush in the opening. That would mean either using on of the other holes or drilling another. Is there something I would be obstructing if I do? I saw 2 other holes and Im not sure what goes there.

After I installed the screw at the base here in this pic




the bottom of the unit still isnt flush



with pressure from behind I can get it sit flush so I need to modify the bracket thats there and create a new one I think on the other side to keep it flush.