From little i can gather, SPINDLE_ENABLE and SPINDLE_DIRECTION are not connected anywhere just supposed to be wired from onboard pin to drive some external hardware. In this case you can re-wire them to the onboard A-step and A-dir, because these from that picture, are also not wired anywhere else. In case that from schematic, the connectors P7-P9 and P8-P10 are close to each other, you could simply just put a jumper to connect them, this is how i would of laid it out. But i cant check the layout coz i can not find the source files. Funny coz i would of expected to be open source.
But between SPINDLE_ENABLE and SPINDLE_DIRECTION, which becomes A-STEP and which becomes A-DIR, that depends on you and how you wire them. I would suggest you wire STEP to 12 because i think 13 may have a led on it and thats no good for a step line.
But between SPINDLE_ENABLE and SPINDLE_DIRECTION, which becomes A-STEP and which becomes A-DIR, that depends on you and how you wire them. I would suggest you wire STEP to 12 because i think 13 may have a led on it and thats no good for a step line.