I decided to do a vertical mount on the 4090 while I wait for a cablemod cable. I'm not sure I prefer the looks, but hopefully it's less likely to burn up.
Amazon.com: EZDIY-FAB Vertical Graphics Card Holder Bracket with ARGB 5V 3Pin LED,GPU Mount,Video Card VGA Support Kit with PCIE3.0 Riser Cable- Black : Electronics
I decided to do a vertical mount on the 4090 while I wait for a cablemod cable. I'm not sure I prefer the looks, but hopefully it's less likely to burn up.