This is from the Wish List where I've posted illustrations of how changing a Layer's Cut Plane does not work: Perhaps I'm missing something, but I'm not getting anticipated results from setting a Layer's Cut Plane. I still see Doors & if I turn off the Sills Class it just removes the the door & the swing; just like normal. Furthermore I can't adjust by Viewport so there's really no point to doing this as I would only use the feature for Reflected Ceiling Plans & this seems to be