My comment would be simply.... As you can tell, I wholeheartedly agree with everything that Corinne just said. In answer to your question of what specifically you could do, for the types of transactions where it's the Canadian that's doing the designing, but the manufacturing is happening some place else, then follow the money. There are income tax returns that are being filed. One branch of the Government of Canada has data on what their overall global income is because that money comes home. Follow the money and from following that money you should be able to find a way—I'm not a statistician—to come up with how you can then put some boundaries around what you're trying to quantify.
I agree with Corinne. What's happening is very large and for SMEs usually that is their first true footprint into exporting. Nothing physically leaves Canada, but they're still exporting.