Tom,
You mention earlier in this thread that the max Vref*2 for setting the current is .72V which puts us at 1.44A. The reason you cite is the reverse polarity diode on the AstroEq board. Assuming I never plug in the power supply reversed, can I just short across (or remove and solder a jumper) it's pins and up the Vref to 1.1V? Pololu's spec shows 2.2A max (with additional cooling). Id put some small heatsinks on the drivers, and a fan in the housing.
Pasted below for reference:
"The DRV8825 driver IC has a maximum current rating of 2.5 A per coil, but the current sense resistors further limit the maximum current to 2.2 A, and the actual current you can deliver depends on how well you can keep the IC cool. The carrier’s printed circuit board is designed to draw heat out of the IC, but to supply more than approximately 1.5 A per coil, a heat sink or other cooling method is required."