Unknown about retail video cards. To see the validated OEM video cards =* Go to the top of this Alienware Desktops Forum* Open, FAQ Alienware Desktops* Open, FAQ Aurora R10
This Gigabyte GV-N3080TURBO-10GD GeForce RTX 3080 Turbo 10G rev 2.0 LHR, 10GB GDDR6X, Extreme Durability graphics card has almost identical dimensions to the RTX 3060 Ti KO that I am currently running in my Aurora R10. I would like to upgrade to the listed RTX 3080 above since Dell is over priced for their OEM GPUs.  Dimensions listed:  RTX 3080 Turbo: 10.51x4.37x1.57 RTX 3060 Ti: 10.59x5.35x2.05   By these numbers, it shouldn't be a problem, but I thought I would ask to see if anyone had any issues. Thanks. 
Aurora R10, Gigabyte GeForce RTX 3080 Turbo?