Couldn't find this anywhere in the threads so decided to test whether the BM EVF works on my BMCC. Obviously it needs power so I bought a d-tap to 4 pin and ran the camera and viewfinder from a v-mount battery.
Short answer is that it works fine.
Focus peaking and zoom in button work - the only things that didn't are the tally light and the info button which stays on default, so you can just turn it off and use the cameras info display.
I'd also just use the focus peaking of the camera as the EVFs peaking also peaks on the cameras display out.
Apologies for the orientation of the images...
Photo 9-09-2015 2 11 59 pm.jpgPhoto 9-09-2015 2 12 17 pm.jpgPhoto 9-09-2015 2 12 37 pm.jpgPhoto 9-09-2015 2 14 53 pm.jpgPhoto 9-09-2015 2 17 09 pm.jpg