I understand how much work it is because I do it all the time. I use SolidWorks but I have found that often I can do a better job and faster in Rhino3D because it is a surface modeler. I click on the visible outside parts invert the selection and press delete and all that inside stuff is gone. I often also remove all the inside surfaces of the shell when I can because you can never see them anyway.
However the real issue here is that it would be WAY less cost if your 3D modelers with access to the original parametric models did this work, rather than having virtually every customer that wants to use your 3D models do it. Take the BRX for example. I expect this task could be accomplished for the whole line in a couple of days effort. On our end it has taken at least that much time just for the parts we use, and no other company gets the benefit from that.
You guys lead big time in product, software, shipping, delivery, pricing, customer support, and its a 3D world. You should lead there too!