I got my BSHS board (with programmed & tested Arduino) yesterday (I’m in Canada, so had some customs delays) and THANK YOU THANK YOU THANK YOU!
I “finished” my Maslow 6 weeks ago and have been troubleshooting ever since - yet to get a successful cut… until yesterday! After weeks of re-making cables, replacing Motors, trying various power supplies, and countless Software re-installing & configuring, I swapped in the board and Shield that Bee sent me and everything Just Works. (My suspicion is that the shield I had was bad).
So, for those fighting with the " The sled is not keeping up with it’s expected position" problem, upgrading your old Shield to this new version is a possible solution.
Thanks @Bee!
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P.S. in case you’ve not seen the warning elsewhere; this new shield needs an insulating pad between it and the Arduino. Without it, you may short the shield’s 12V input to the USB jack below, to fry your Arduino (like I did 
… good thing I ordered the spare Arduino from Bee when I ordered the Shield)