Do you have your GPU under water?
If so, you may be able to use an "A" instead of a "B" connector (or vice versa) and have the cable run on the other side of the GPU (LINK)
If air cooled it probably will not work as the cooler is too thick
Interesting question.
I thought about that, as my GPU is mounted on a vertical riser.
Very little place between the motherboard and the vertical GPU. As I have a big case, it would fit, but the ampinel heat sink would be few millimeters to the RAM. So according the manual, not a good idea at all.
(And with the second "type" of Ampinel, of course pulling the cable in front of the GPU isn't esthetic, but also it wouldn't fit at all because of watercooling tubes.)
An ampinel for vertical GPU would be great.