My Maximus z690 Formula came with the ROG Graphics Card Holder which is shown in the photo below. Obviously, that is not my card or motherboard, just a photo from the web - but I have it installed this way with my Tuf 3080 ti. I also have the Phankeks P600s GPU Anti-Sag Bracket installed (it is a screwed in bracket which tightens / sandwiches the metal foot of the GPU to the frame of the case so it can't move..
I'm curious if anyone else uses the ROG magnetic holder as well? My only thoughts are that the holder doesn't have anything that absolutely fixes it in place (e.g. screws, zip tie) except the magnet which holds it to the floor of the case. The holder is also wedged in place between the card and the case floor (it has a rubber tip on the end touching the GPU). I don't care how it looks.
After building a 6k machine my OCD paranoid self can briefly imagine the remote possibility of the ROG Graphics Card Holder somehow coming loose and shorting out the $700 motherboard and $2000 GPU. Of course, in order for this to happen, there would have to be a 7.0 earthquake centered under my house or me on drugs placing the case on it side and shaking it frantically. Even then it shouldn't come loose.
It just seems odd that it has nothing but a magnet holding it in place. Just curious if anyone else uses it. Joking aside, it's actually a pretty simple and effective solution. I had to remove a plastic cover off the floor of the Phanteks case for it to fit, but it works well - especially combined with the case's solution.