I also do "it's a miss if it rolls off the table" - though I usually start with a warning. I've had too much "hyper-die-rolling" that our group has actually coined a term for it. People getting up, searching for lost dice, disrupting the game, making people get off their seats, searching under furniture and bookcases, taking three times as long to make a die roll because they can't hit the table. It's rude, and if you can't control yourself, you miss and we move on.
If it take longer than a couple of seconds to find a die that has fallen off the table, the person just uses a different die until a break or end of session and looks for the lost die then.