AOE knockback rearranges the inside of the dungeon. Walls, floors, so on and so forth. It has... interesting and unforseen consequences, such as making it so that to get into jail cells you have to kick parts of the wall in instead of the bars themselves. And other equally bizarre occurrences. Performed with the Unarmed AOE skill if it matters.
I think thats a feature, I would use some knockback abilities to knock off items surrounded by water, or sometimes create choke points and get into places. Once i even used broadside on a wall too much and the wall collapsed
I do not think you understand. It does not simply destroy things. It physically shifts the entire dungeon, radically altering the landscape and even moving where wall-mounted gargoyles are placed. This is not simply a matter of "it allows you to move things around." This is a matter of "when you use this ability you can watch the entire dungeon's terrain shift a number of squares in random directions, completely screwing up everything, putting walls where there should be none and allowing you to access the edge of the map where there should be walls."
I am not using any mods, just the expansions.. After some experimenting I discovered it inconsistently worked on walls. I also discovered that sometimes it rearranges visible objects without changing their position. Before. After I used some kicking (you can see it selected). Yes, I can't walk into those spaces I "cleared" since the walls are still there, they've just visually vanished.. further, you can see how a lot of the special details on the floor (glowing cracks) have rearranged themselves. Again, purely visual.
Although i know most about the things you are talking about and how to recreate them, in your most recent post, I don't recall not being able to move into a cleared space.