First of all I must congratulate on the awesome CrossFire performance with Deus Ex, my R9 390 CrossFire at 4K performs like a Titan XP. I hope this trend will continue, you should create an aggressive DX12 marketing plan for the AMD's CPUs and GPUs.
But there is a little irritating issue with Radeon Settings and Afterburner. When I start playing a game, the second GPU fans do not work or work at lower fan speed as often as not. It happens only with the second GPU.