I believe the answer to your question is yes as I am currently doing this with a G540 but it may depend on the breakout boards, Gerry seems to be an expert on the subject and hopefully can chime in.
In my case, X, Y and Z are wired together and A is separate for squaring of the gantry to the table.
One thing to keep in mind is that you will need some adjustments on the sensors for the X and A axis to square it.
Adam,
Gecko G540, Rack and Pinion Drives-X and A axis, 1/2-10 5 Start Acme-Z Axis
4-THK HSR 25 Linear Slides, KL23H2100-35-4B, Power Supply-KL-600-48 48V