One other limitation that I have been thinking about with regard to the MicroMod 'standard'.
The standard assumes a 22x22mm board with specific fastening making both ends of the board unavailable for mounting high speed connector directly on the module (where you need them), this was an important design feature required for BlackEdge. Thus if you want to support HDMI, USB3, MIPI CSI etc you are out of luck. With BlackEdge we anticipated mounting these on the core board directly using industry standard connectors where possible, clearly this has not been considered in MicroMod's standard..