Work flow is as follows:
Modify → Change Parameters
Set desired width and height of multiboard.
A value of 1 for TopEdge and SideEdge will remove the respective diamonds from that edge.
If you're using fusions' built-in 3d print utility, select the entire multiboard component from the sidebar, instead of selecting individual bodies.
To prevent lag, this uses a rigid group instead of a boolean operation, but the resulting .stl is identical.
The author remixed this model.
Used the step files provided by SolBro, (In turn deriving from Keep Making's Design), to create a generator for fusion.
SolBro's design is under incorrect licensing (CC-BY-NC-SA Instead of CC-BY-SA, as dictated by the original multiboard design). I am unable to add it as a remix source without also incorrectly licensing these files.