Those plastics really don't help much, do they?
You can try using a piece of plastic cellophane, from a string wrapper. Thats what I use. It usually doesn't last that long.
The screw-in
trem arms, if done right, can offer better control over how tight/loose they are.
But for a pop-in, I wish I had an answer. Mechanical parts should be designed and manufactured in a way that they should not easily come loose. It is poor design, reminiscent of American quality standards.
"unparalleled craftsmanship" means "not as bad as the other guys". Time to set a higher "bar"