I opted to move away from the MB6582 button-matrix design and, instead, use standard shift-registers mounted on my control surface boards. Less modules, less wires to connect between boards, etc. This is primarily because I am limited in Eagle Standard and can’t create a single control surface board (where a button-matrix would certainly make more sense).
Thing is, I’m so used to using diodes for buttons but with just using shift-registers, I assume that they are no longer required (but probably don’t hurt anything either)? I know the pull-up resistors are required to prevent phantom button presses and things but I assume the diodes are optional?
Also, when does an isolation plane make sense? How about a power plane? The bottom plane is for ground but most of the top wires are for power, so I was curious if I should use an isolation plane, or if a power plan would even make sense. I hate wasting copper 
For the curious, I’ve included the first board I switched over to using on-board SRs. There’s quite a few SMD parts on it but I figured that would make the layout easier, which seems to be the case (though I have more vias than I’d like).
EDIT: For to ask about grounding unused pins for the input SRs? Yes?
