Leakage - Production start-up issue IMO minor
if you can still (somewhat) inhale with both holes plugged, potentially leakage at the interfaces eg: 1) filter end at heating element and/or 2) filter seam.
for mine, tape wrap seam of filter end to heating element, tape cover LED hole, and carb the other hole.
100%
(a plastic id tube wouldn't help because it would isolate the nano filter from the airstream)