Man... not everyone uses crappy hicaps.
And.. I assume that the idea of putting BBs in mags is to "make sure they aren't real" but seriously, this isn't needed at all.
There MIGHT be problems if there's visible fake rounds (as real-looking bullets) but even then, most will come through without problems.
Other mags without fake rounds will go though. It may take some time, but that's canadian administration, so nothing surprising.