Looks fine to me.
If we forget for a moment that it's a sliding dropout and treat it as a normal vertical, the important thing is that where the OEM2 plate secures to the bolt, or Monkey Bone in your case, is behind the dropout. Rohloff advise that the torque may rotate the hub out of the dropout otherwise. I've just fitted a Monkey Bone to my folder, the manufacturer placed the hole for the securing bolt forwards, so either they didn't know or Rohloff have changed the advise, I rode several thousand miles in happy ignorance! I can't think of any reason why the sliding dropout should behave any different to a fixed one.
Maybe the reason you can't find anything similar on the Rohloff website is that they'll assume anyone with sliding dropouts will go for an OM1 plate and a Rohloff specific slider, which is probably what I would have done.
I know a couple of people with seatstay cable runs, though I can't remember what dropouts they have, the only caution is to not let water run down the cables into the box. couple of things you might do - a few wraps of insulation tape on the cable a cm above just to break the flow, and pack the heads of the hollow screws with waterproof grease.