Another scenario - I use it very often dimension with a reference to another (fx), or with some formula, but it would be nice not look like current dimension. In fact, it can be constraint (same lenght), maybe also same amngle, maybe :dimension constraint vs. visible contraint. Some variant is also possible and similar to lines - dimension in :construction mode" - so it is lighter, maybe dashed, but visible very light (only dashed is not enough).
Ok, I am creating new Fature request.
