Mechanical switch tester in a grid layout. Number of rows and columns are variable.
I have measured and modelled a kailh low profile switch (see measurements.scad), feel free to adapt it to your own.
Any elephant foot you get on the top plate is useful for keeping the switches in place. Mount the plate upside down (foot on top) and your switch will clip over that.
I guess you could use this to make an actual (macro) keyboard.