I have a M2 and a M3 standoff kit... but they don't work with the supplied standoffs... wondering what size they are.
I want to mount my pi to a back plate that can be easily removed from the enclosure, I would prefer a base that the PI clips into... but can't find one, and I don't have a 3d printer... so am thinking about using VESA mounts for the pi and attach the pi to that...
The standoffs that fit the pcb board are M2.5 @6mm if I remember correctly.
The wiki shows M2.5 11mm + 6mm (if I'm reading it right :D).
http://hivetool.org/w/images/9/98/DevKitPartsList20160116.pdf
Consider using Velcro to secure the Pi to case, works great for me!
I don't use standoffs, I find them unnecessary the connector provides support, I add a dab of RTV or rubber cabinet stop to the HDMI connector to prevent grounding the PCB.
Adrian Ogden