I'm not familiar with the "pinch" technique - can you elaborate?
Yes, that would have been helpful. I thought that after getting the cartridges aligned and partially inserted into the cylinder, instead of pushing against the cylinder (and yoke screw) to release them, I'd place my thumb on the release button and place another finger or two on the other side of the cylinder for support, and make a pinching motion to release the cartridges. This way, I figure there shouldn't be as much forward force on the yoke. I don't currently own a COMP II or similar speedloader, so I haven't actually tried it.