Registration and Flipping multiple parts

Hi, new to Kiri:Moto so if this has been answered happy to be pointed to it!

I am accessing Kiri:Moto from OnShape (Safari). I am milling (Xcarve Pro) several two sided parts simultaneously. If I bring the parts in as separate, the Flip operation flips each part locally as opposed to flipping the stock. If I bring in the parts and group them, the flipping operation works (it acts as if flipping the stock), but each part still receives its own registration, rather than the stock being registered once for all parts. Is there a way to register just one part? Or the stock? Below, you can see the registration for each individual part. Thanks!

well, to be honest, I never tried the flip operation with a bunch of separate parts. I can see this could be problematic. the code is part-oriented vs workspace oriented.