Uuuuuf!!!! As a spintop developer, when the process is in such time, it is difficult to add changes.
In my experience, the problem of the crown isn't that, the real problem is the ring. A bit of negative angle in the inner side of it will be resolve the problem.
The air intake it is very difficult to resolve..... cheap! The easy way is retouching the molt of the crown to add the neccesary plastic to close he holes and tabs grooves, but don't forget the circular groove within the body and the crown.
Indeed the plastic tape solution is the best one, and add personality to the top.
And the most critical..... spin well?
About the video. Great snag the zorro! But I appreciate specially your technique to pull the string making a large arc up your hand to avoid string disasters as knots.
Ultra's 5 star Mexican top is great. I buy five extra colours to Baldufado and broken the "Reyes magos" letter :-D
Ps: Reyes magos. In Spain the christmas gifts to the kids are carryng by the three Reyes magos using camels the 5-6 january nigh. So that christmas holidays are longer hear. The schools doesn't open until january 8 as soon.