Look at the incidents that have taken place. The bottle has not failed, as in burst, it has always been a reg which has popped or seperated from the bottle. The structural integrity of the bottle here is not in question, TUV have tested to I believe over 900 bar of pressure (300 is around 4500 psi, so we're talking 14000psi ish) and the bottle did not burst. However, what is the nature of the thread testing with these cylinder tests? Could the thread be shallower or of a softer material than mainstream bottles? I'm sure it has been looked into, but it's not been mentioned on here. I personally used a Stako for a year and only got rid as my local site stopped filling them, so it was useless to me. It never bubbled and would hold a fill for months at a time.