I am currently testdriving a Tek scope and found one issue on the board that was undetected so far.

The MISO signal picks up some cross-talk from the parallel SCK lock line during the cycle that writes the register address to the MAX11300 chip. This is how it looks on the scope.

The amplitude of the signal is to low to cause any glitches, but a different board with a different flavor of Arduino might look differently.

A pull-down resistor should take care of this issue and finally there is a good reason for the next revision.