I'm going to use 2 stepper motors for my X-axis. Can I use the same connections on the B/O board to do this knowing I will need 2 separate driver boards.

Yes, absolutely. If you need two motors for a single axis, you will want to use the same terminals for pulse and direction from the breakout board. More specifically, you will wire the step/pulse pin to both drivers, and the direction pin to both drivers. If the motors need to turn in different directions, simply swap the A and B coil connections on one of the motors. Additional Information: i have checked the cnc machine for any flex and there is none but i still cannot cut circles they end up square.have checked calibration and it is correct but if i run at 4000 mm feed all comes out correct but if i change feed to say 2000 mm it makes the part small, like in tiny.