You should export your files to iges or step. I hope that's what you mean by defeaturing. You can also try 3DPDF. That's safer.
My deliverable to my customer is a "native" SolidWorks file. sldasm, sldprt. I like the defeature because it locks out "recognize feature", once it is saved. But i guess they could just re-save the file and re-import it and have the ability to use it. Just need to export to a dumb model, and it seems like even in my own mind i might be stuck with STEP or IGES. Which i have plenty of macros for that.
I think there's a dirty way to do this.
if it's a part, add it into a new assembly and then save it as a part. When you do that, there should be an option to export the exterior faces only. I think this would do it for you.