Does it matter at all if its on the left or the right? Seen most builds install it on the right side... my set up has better clearance if its on the left.
No. But you either have to switch the motor wires or invert the motor direction in your setup. If it were me, I'd just keep the motors wired the same and invert it in software. If you're using a grbl based controller, you'd change parameter $3.
You might not have to change it. Basically, if you tell it to move X+ and it moves X-, invert the direction in grbl settings
