Okay, this is a problem we literally solved in the early 1980s. Back in the days of the original IBM 5150, there was an agreed-upon "full length" card size. T

Okay, this is a problem we literally solved in the early 1980s. Back in the days of the original IBM 5150, there was an agreed-upon "full length" card size. The case had a little plastic rail attached to the front panel, so a card that length would fit into it and be braced at both sides. For a $10k card, they could easily say "Only these specific cases"-- which have an appropriately positioned rail. These days, it might need to be a full steel buttress, but still, a lack of standardization created this problem more than anything else. I prefer a flat-motherboard case (an old CoolerMaster HAF XB) so my beefy Radeon 6900XT doesn't sag or require something to prop it up.