Hi just seen your post.
I have the following set up shown below.
Power is coming from the Switched ACC cable in the headlight. I used a cheaper holder from ebay (Orange) and then I used longer screws to go through the holder and into the mount orange. I also filled up the distance required with rubber blocks to help with vibration and incase handle bars hit DMD tablet on crash.
Note to fit the longer bolts I had to cut the raised sides from the tablet holder so the heads would fit, so far it has held up on ACT Italy / TET routes with no problems. All cables fit nice between the Tablet and small windscreen
Holder cuts
