Thanks for all of the replies. billb, yes creating surfaces from solid do hold their shape. In our case, the surfaces had holes and counterbores in them. We created the surfaces from solid, then filled holes. That runs perfectly fine. The issue was that the model and surface levels were both toggled on along with a window selection for drive surfaces which selected both the model as well as the created surfaces. Simply removing the solid from the toolpath geometry left us with only the user created surfaces as drive surfaces which works just fine.

I have a co-worker that used a Surface Finish Parallel on a 3D nose. I noticed that he window selected over both the model as well as his surfaces that he created (in order to remove holes). I didn't think anything of it at the moment but when he ran the toolpath in our 3-axis Doosan/Fanuc controller, the tool (ball endmill for surface operation) had a very odd step over and left scallops all through the narrow end of the part. In hind sight, I diagnosed it by viewing a backplot from right view and saw that the toolpath was jumping and stepping at the bottom edges in a not familiar way. We went back to his geometry and proved that he had both the model (unsuppressed) selected as well as his created surfaces (with suppressed holes) selected which were coincidentally one exactly on top of the other in space. We removed the model from drive geometry and just stuck with his created surfaces and it fixed his issues. I was aware that he window selected all of it at the time and understand that is a "dirty" way of selecting surfaces/geometry to drive but was simply unaware that it would create an issue. Can anyone possibly explain the "why" it would confuse Mastercam as it did (reading 2 separate drive surfaces/model selection in the same locations in space)? If needed, I may be able to replicate it and upload a file but just hoping someone understands without having to recreate it. Much appreciated.