Working North of the border, where there are some quite large lumbs, our RVC looks like a demented childs jigsaw puzzle. In all cases however descent instruction are not given until an ac crosses the line into the next sector. This may be a Mil thing, as some of the ac can quite literally point themselves at the floor, or it is a civil interpretation as well, I can not tell you. However, descent instructions for civil ac are given in the same way. without it I would imagine you would have to give a conditional descent profile ie 1000ft per mile and a point to be level at in order to counter lost comms. All in all a bit time and effort consuming if you are busy. Far better to say descent report level abc, advise approaching for further.