Markins Camera plate issue.

anyone have any issues with these hex nuts coming loose during use?

Not so far - touch wood.

I've only started using the Arca-Swiss system this year, so my experience is limited.

Richard

It shouldn't be a problem. As part of you general upkeep of your equipment, you should periodically check and tighten the screw.

Absolutely not! The Hex screws only require moderate tightening and I have never had one of them even begin to loosen despite a lot of use.