I have a great Korean marinade recipe. It is recommended for bone-in, beef short-ribs. I believe, the regular-cut kind is specified (i.e. two-three inches of meat covering the same amount of bones as opposed to the cross-cut variety.) It goes on to recommend that you cut the meat almost to the bone in 1/2 - 1 inch increments before marinading. Finally, they are to be grilled 2-3 minutes per side for medium rare.
If short-ribs take 2-3 hours to braise, is it possible that they can be grilled in 10-15 minutes and be eaten medium-rare without being chewy? I've seen other recipes that require an hour or two of baking before the ribs are grilled. The recipe does recommend rubbing the meat with a kiwi before marinading to insure tenderness, and the marinade does include a small amount of lime juice.