I did notice with catalyst 14.7 you no longer needed the inf fix to get 6 cards going in doze, maybe you can go more than 6 now without any tap dancing...
It was already tested. Problem is not 6 GPU but more than 8 GPU. 14.4/14.6/14.7/14.9 - tested. Problem is in amd kernel. amdkmdag.sys - ATI Radeon Kernel Mode Driver and amdkmdap.sys - AMD multi-vendor Miniport Driver causes this problem.