I have ordered a D+ too, but mine hasn't shipped yet. Apparently they are having issues with titanium colour.
It's the first production run, so delays are to be expected, but it is getting a bit annoying.
There's enough photos that I feel like the case exists, but this new update is really weird.
I sent a message to my agent asking to cancel and place order at new store; hope I don't get screwed.
If you want a quick estimation, measuring the top of my spare PCIE connector (11.5mm), assuming an angle of 45 degrees then the top is ~8mm above the fins area. So maybe ~6mm?
Might have to rely blocks with the ports at the rear of the card; I don't see any other way of achieving it. Even then, those blocks tend to be thicker than usual.
Plus, what pump can you fit in the remaining space that can support 2 radiators?
Have you looked at adding support for Flex PSUs...