You can probably mount those power resistors off the board... I don't think a little extra lead length will make a difference... there will be some power running through those leads so watch out for any data cables running near the wires.... just like you would with motor leads. Shouldn't be much of a problem. Perhaps you can figure out some way to mechanically mount the resistors since the leads will be too long to reliably support them.

You know, GeckoDrive puts the current sense resistors on the motor side of a connector so that the setting "goes" with the motor if you switch motors out. I don't suppose another header would happen to fit in place of those power resistor pads? Then you could call it a feature instead of a bug! LOL...