Someone asked for a pic of my older S1 ground down pulley to make it work with the seriously good Severne Cyclops. I used a Dremel with the pictured brush styled sanding wheel to grind down the middle pulleys just enough to allow the down haul rope to squeeze through. You want it a snug fit so the rope doesn't jump pulleys when you're pulling down. Still works with the normal extension but you need a bit more care to stop the rope crossing.

So easy to rig and de rerig, don't know why someone didn't think of it before.