Literally just back from there. Know exactly what you're talking about, although no squatters when we went. The way you're talking, you'd need some slings to drop in given the height of the only open point there. There's one other place to get in though, although it sure took us a bit of time to notice it. Felt like a numpty once we did.
On the way out though, in between the two fences (assuming you went the way we did) secca came flying round in a car and spotted us. Lucky we were in between, so we got out before he could get in the point between the fences.
As a side note about demo, we did notice there's a big demo company logo on the way in. So whether it is or not, I can't vouch for, but it may be happening.
