Nev.... the quadrant system does work, provided it is used with plain and simple language that lets everyone in earshot what needs to be known. What is so hard at reporting at 30miles South and tracking for a 10m final 29?
Suggesting that the VFR should have a pile of paper available in the off chance that he might conflict with a Jet using IFR lingo, is neither practical or possible.
The answer is for the IFR/Jet to make calls appropriate to the circumstances and also to ensure that the words used are understood by the pilot with the least experience in the area. Saying that it is ok to question if you don't understand etc is fine, but it does jam up the frequency when an appropriate call in the first place would avoid that.
They used to call it Airmanship, but then they don't seem to teach that any more do they??
(another Cub fan...)