Castle: the building with the holes in the roof, can be used be ullapool demos to skip the following traps, such as at spawn where demos can jump on the block and then jump all the way past the spikes, and the following building where they can walk on the falling roof and jump on top of the fans that blow you down. They can also jump up on the third one to break the smashing blocks, so they will no longer move up or down. If they get stuck in the down position, it makes them unpassable unless you have the patience to walk on the ledge and not fall off.
I've fixed these except for the first building, as I can't see how a demoman could jump from the block to past the spikes, since the gap is pretty huge.
Cocainum: There are lots of invisible walls that demos can ullapool on and run around, allowing them to skip platforming and guessing traps.
Can you give specific examples of where these walls can be used to skip multiple traps?