SOOOOOAPYMEISTERi think its more useful to stop yourself from fall damage more than actually hiding because you cant stick to the wall (ive been trying for months it doesnt work) also the red teams side is harder to pull off than the blue teams side idk why.
that is a coordinate wallbug. When a wall is near a power of 2 units from the map origin you can do instantaneous wallbugs (just resetting your vertical velocity to 0 over and over) like that. It's only on blue side because the map origin is not at the geometrical center of the map so the mirrored side is at a different distance from origin. However, on red side if you go through underpass and onto the bridge, you can coordinate bug on the wall there above the doorway, which you can't do on blu side. So each side has their own special coordinate wallbug (this was obviously intentional). When you do the alley one on red side you are texturebugging on the windows or where the walls starts, so smaller timing window at only those specific points.