https://www.bitspower.com/support/875/waterblock-compatibility-for-x299-asrock-taichi-clx
The answer is not true. I have mount this Block without problems on a Asrock X299 Taichi CLX with Rev 1.1.
Have full contact with CPU and VRMs, the holes fits perfectly.
Have Asrock rework the X299 Taichi CLX so that is now compatible ?