Are you sure it fits perfectly? I got my tank replaced, and put my old Shift Tech cover on my new tank, and it is pretty close, but it does NOT fit. The double sided tape is not strong enough to bend the cover the small amount it needs to perfectly fit the tank. I have discussed this with Guido, which is probably part of the reason why he will not state that it fits until he can do an official test himself.
I know that I installed my tank protector correctly, as it is the second time I have done it, and it fit absolutely perfectly the first time, and the second it is 1-2mm away from fitting on all sides. But I wouldn't take my word for it, the only word I'd accept on if the Shift Tech works or not is Guido's word, and until he does an official test, you will just have to wait.