The welfare hutch one is designed to be able to just undo the wingnuts with one hand and slide the wood out of the way. The runaround one is designed to need a screwdriver and a spanner to undo it.
The runaround mark 3 door only has one wingnut. It has never had multiple, and neither have any of the other doors. The mark 1 and 2 have had 2 swivel clips, but never have they had 2 wingnuts. (The 2 swivel clips on the mark 2 design are shown in the main picture here:
http://www.runaround.co.uk/collections/frontpage/products/runaround-door-1. The main picture is the mark 2 design, the pictures below are the mark 3 design - clamped totally on one side, and 4 swivel clips to hold the blocker plate on the other side). The only design to use a wingnut is the mark 3. Really not sure where you're getting your information from. Have you actually seen a mark 3 door in the flesh, or just the mark 2? You can get the runaround tube out of the mark 1 and mark 2 connector, as we've seen here. You can't out of the mark 3 connector, or if you adapt your double door to put the 2 sets of half moon acrylic pieces on the one side as Santa suggested in her original post. I am comparing the mark 3 door to the welfare hutch one, as only the mark 3 door is currently available - and runaround advise anyone with the mark 1/mark 2 to update to the mark 3 for this exact reason.
If the runaround wingnut is placed on the outside you still need someone holding a philips screwdriver into the screw in order to undo the wingnut, so how easily the half moon shape swings out of the way is irrelevant - it cannot be undone without a screwdriver and a spanner. The welfare hutch one is designed to be undone with no need to hold a screwdriver in the other side: ''it only take a couple of turns of two wing nuts and it's done'' A fox could get into that. A fox is capable of spinning things - as we've seen in this exact thread, with the old design runaround door. The entire reason Santa's pipe has come off is because it was the old door, with 2 spinny clips. Spinning clips are not an appropriate way to connect something that is supposed to be fox proof.
Plastic can snap yes, if a predator manages to get its entire jaw around the exact area where the pressure builds. However, notice there's no damage to the runaround door, even when the pipe is removed? The fox could get his jaw around it then. No damage. Yet the wood is completely messed up. There was no easy place for the fox to get its jaws around the wood on Santa's set up, yet look how much he's destroyed. The welfare hutch connector to a hutch looks pretty good in terms of nowhere for jaws to get around, but the mesh one is is a little more worrying as there's space to get their teeth under.
And, as I've said before, the runaround door also is designed so that a fox cannot fit its head or shoulders through. So there's another layer of safety there too. The welfare hutch one is completely open - a fox only needs to undo a couple of wingnuts and chew through some wood and it can stroll straight in to the rabbits.
Wood is a far less safe material to use for connectors. It is simply too easy for a predator to get through as we've seen here. If the wood is wet, damaged or old it'll be a lot easier to get into, as well. As I said in my previous post, I have messed around a lot with both the cladding and mesh types of the welfare hutch connectors, and I also own both the mark 2 and 3 runaround connectors myself.
There's simply no contest.
Santa, if you read this and you have the time between trying to fix the enclosure, would you mind posting some closer pics of the damage to the wood and the damage to the pipe/runaround door (if any?)