bcd issue

Hi, I am part of an FLL (First Lego League) team, and I was wondering what type of mechanical inflator do you use for your BCD? We saw a 2020 post about a problem in the hose and inflator, and could you state any problems you faced while using a mechanical BCD inflator? (By the way, it was this...

I bought Hollis ST Elite System with LX2 weight pocket. The pocket came with 2 set of book screws. However, last year one of my book screw came loose and gone missing mid dive. I tried buy the book screw that listed on Hollis website as well as my LDS but it seems like LX2 weight system used...