@emily may I suggest your constrained in the same axis twice aka one rail could be rolled 90 degrees to make them non-conflicting?
I also had fun keeping the drive screw parallel to the 'control rail' on my machines, I ended up leaving the lead screw 'floating end' and making sure I had a good thrust bearing on the motor side.
On the printers, I dont have to worry about the rails being parallel, just 'level' The bed follows the control rail.