It's a shame about the Alphacool block causing clearance issues but we have been told that they are revising the back plate and that they will send you one to complete the tests.

Regarding your point about the thickness of the pads being 3mm to make sure the soldered tips do not touch the back plate its actually a growing problem we are seeing this a lot more with recent generations of GPU's. It's also the most user friendly method of making sure there is not an issue unless you use a method like this from Swiftech that is not exactly friendly for the customer.