I find that when the square is held perpendicular to the wall, it is much easier to access.

The model was designed to accommodate a 4 inch iGaging double square as seen in the photos. It is essentially a skinnier, stubby version of my combination square holder.

I greatly prefer the stability from the big folded screw version of the multiconnect v2 connectors which I've added as a second plate.

Additional multiboard flush mount connectors can be found here, or connectors with offsets can be found here.

Credits to Jonathan (KeepMaking) for creating multiboard

Credits to David D for creating multiconnect