Rat is correct, interior strapping is not covered by the CRL.
FYI, it is possible to set snaps using split rivets, here is my armor and the riveted side is detachable:
I have this one: https://www.amazon.com/Anker-PowerCore-Lipstick-Sized-Generation-Batteries/dp/B005X1Y7I2
The only thing I don't like is that the power button is hard to reach with it mounted to the helmet, they make a 5000mAh one with the button on the side that is a bit bulkier but may be a better bet.
I have seen people sew their gaskets to the undersuit to save time kitting up, it is doable but as I still don't have my FOTK yet (thanks, Anovos) I can't comment on which system is "better".
I would like to add that your armor may vary slightly in height, the important part is the top and bottom rivets, the middle one should be equidistant from those.