Fair enough. In that case, I really do think that the addition of an extra bit on each block would be a good thing. It only needs to be an "Is toggled" check. The main problem I see with this, though, is that it has a different problem in function. It can be just as much a pain to make certain that a wall does not go under certain blocks, and can affect the look of things. Sadly, the only alternative I can think of to address both does not fit here, as it would require a device rather than a wire (that being a placeable item which can store two blocks/walls and toggles between them).