This hexagonal Skadis board has true 40mm spacing between all holes and works for multi-peg accessories.

It has 6 screw holes and you can use any 2 or 3 as needed for your walls. I have a very uneven wall texture so designed it so I could use any 3 screws and make it secure without rocking.

You can print with or without supports. (they're only needed for the screw holes but i printed all mine without supports with only some stringing from bridging)

Accessories can fit in any of the holes even at the top and bottom and the boards can be used upside down just as well as all of the wall standoff has been cut out in those areas.

The hole spacing remains compatible for vertically connected panels but not for panels to the side. 

Multi peg accessory compatible.