I have a couple short GPUs that aren't long enough for my open mining rig frame, so there is no support on the back of the GPU. They do sort of hang there if you screw them in but didn't seem like it would last long term.

The support clips onto the frame and is sturdy enough to support the back of the GPU, so it no longer sags (see pictures).

The GPU I was working with is an EVGA RTX 3060 XC and the frame is a Kingwin.