My card arrived and it is a monster. At least 7mm taller than the 2080 it is replacing. Before I order the Cablemod thing I figured I would just stick it in the vertical mount in the case to see just how bad it is. My observations/experiences:
1) It conflicts with the "Big" Noctua cooling tower for the 3Gen Threadripper in its "centered" position. at a 6mm offset it just barely fits
2) In the stock vertical mount the card clears the case cover, but it is close.. <20mm from the fan to the glass.. Too close?
3) I ran some stress tests and the OC Strix card clocked in at 110% of a "normal 3090" (whatever that is) and never went over 75C (slowly climbed to 74C and then plateaued there) on a 30 minute stress test.
4) The air cooled Threadripper also got warm during the test getting up to 72C-73C range during the stress test... (Normally it idles 30C-45C and under load with the 2080 it never went over 69C. The threadripper is not overclocked.
So I think I'm good... I don't game on this machine... It is mostly used for 3D work and video rendering... Even with a monster Solidworks project the fans on the GPU turn on...at slow speeds.. then cycle off. I'm going to run it like this and see how it goes.