Lens collar rotation

Hi, I see a lot of people using a lens collar on a tripod and rotating their camera from landscape to portrait, quickly and on the fly. I've got the RF 100-500 and the collar seems a bit tight and unable to close all the way. If I loosen the thumbscrew a bit I can rotate the collar, but if I turn the thumbscrew much more, the collar opens up and comes off of the lens. So there may only be about a half turn of the thumbscrew between being loose enough to rotate the collar and having the collar fall off. This seems very dangerous to me as a slight miscalculation could cause my entire rig to fall to the ground.

I also have the 70-200 2.8 and I notice that the collar seems to fit a little better -- at least it closes all the way. And with the 70-200 there may be about a 3/4 turn of the thumbscrew between being loose enough to rotate and falling off the lens. That's a little better than the collar with the 100-500, but still seems a little risky to me.

What am I missing here? Does Canon endorse rotating your camera on the fly by either leaving the collar a bit loose, or loosening, rotating, tightening?

I am attaching pictures of the collars mounted on both the 70-200 and 100-500 and you can see the gap on the 100-500 where the two halves of the collar don't quite meet each other. Is this normal?

Considering that the collar is bearing a lot of weight, and basically holding EVERYTHING from crashing to the ground, it just seems like a mistake to loosen it up during use unless you have the camera and the lens fully supported until it is tightened back up and tested.

I haven't used these collars much so maybe there is something I don't understand.

Any thoughts or insight would be appreciated. Thank you!