Looking more, I don't think it matters.
For cars it's more about the internal cooling vanes rather than the direction of the holes.
I can't imagine your rotors have cooling vanes, so you should be good either way,
"It is not possible to tell if a drilled rotor is installed properly, simply by observing the drill pattern. Different manufacturers use different patterns with spiral "arms" that appear to lean in either direction, regardless of the internal cooling fin orientation. For example, StopTech AeroRotors, used on their big brake kits, have a drill pattern that appears to lean to the front of the car. Porsche OEM rotors have a drill pattern that appears to lean to the back of the car. In both cases, the internal cooling fins are properly oriented, leaning backwards. But the drill pattern is opposite. This is why Porsche mechanics often install StopTech big brake kit rotors backwards, despite the big "L" and "R" stickers on the rotors! They're relying on the drill pattern, rather than the direction of the internal cooling vanes."