Basically the kit has to be incomplete enough and sufficiently disassembled that Transport Canada does not consider it to be a "vehicle." The problem is that Transport Canada will not tell you in advance what qualifies.
Probably the crew with the most hands-on experience on this is the FFR guys in Canada. You could check with Al Beix,
the official FFR rep for Canada, or with any of the individual builders who handled the importation themselves. Suggest you post something on the
FFR forum.