I just wish I hadn’t used the only good piece of final-project-wood I had. Looks like it’ll be made of pine now 
I am still having some slipping in the Y-Axis as well.
Try increasing you Y current more, that seems to be the issue with mine. 
I keep bumping the pot and it seems to be working because the slipping is happening less and less.
But because one chip is driving 2 motors I am concerned that I will start having heat issues in the chip.
I think I need to put a temp probe on the Y driver chip and see just how much I can turn it up safely.
I will post my results 
Well temp is not an issue.
The chip has a max operating temp of 150 C
With the pot turned up to max (any higher and the steppers start to vibrate and do weirdness) and the chip never got above 22.7 C.
So as long as the cooling fan is on I don’t think overheat will be an issue with the GShield.
What size steppers are you using 17 or 23?
23