Anyone worked with machining through King Starboard?

Have a sign that may be using starboard color core machining through the face in large-ish areas exposing the core. Im wondering if anyone has any experience with trying this and how one would deal with the machined area that doesnt have the factory extruded surface and will surely show tool paths. I have only done small items with thin color core where the machined area is small enough that it really doesnt matter. The other option we are kicking around is cutting the text for this sign out of something like Dibond (red) and the background out of whatever color the customer finally chooses (could be solid color or brushed stainless, etc). The larger components of the sign would have to come out of 4x8 sheets minimum.

We are going to machine some color core scraps but Im pretty sure there is no way the floor of the larger areas will be clean and Ive never seen/heard/read about any way to heat or solvent seal?

Thanks

Did you get a chance to experiment yet? I just did my 1st Gatorfoam project yesterday and today. Figuring out how to clean up some of the foam edges. I was also wondering if it was possible to "pocket" cut this foam. Have not had a chance to test it.