Water area have "Attach to movable" as a way to move water area via movable just like background whilst still being water or acid and have liquid behaviors - not sure if this is possible but it would be a nice addition to attach to movable and I had this idea and now I'm spreading this out as it still hasn't been added and I just hope it does in a way
Lights/Lamps "attach to movable" - this one isn't necessary but just for fun if this is possible why not have lights or lamps that are attached to movable and will be a moving light/lamps but it still won't generate lighting effects for the shadowmap as PB2 uses a static lighting and not a moving one but I did hear that PB2.5/3 will have a better shadow logics then PB2
Walls "Attach to movable" - This one is just a joke I don't think we need this LEL but it would be cool if we had custom images of such walls I bet ChaoSquid has already made them but they require no grid-snapping but whatever I bet someone can easily make them better and have them fit for grid snapping perfectly and yes and no