Sg, by the time you read this, you will probably have been subjected to my thoughts about about the relationship between surface area and volume in the kitchen. You will, by now, understand why tiny cookies taste different from large ones made from the same dough, what is wrong with science fiction movies that propose greatly enlarging or shrinking things while keeping their proportions intact, and what the one has to do with the other. So you’ll immediately see one of the advantages of flaying your hot dogs before laying them on the grill.
Another advantage is that the suckers are hot. It is a sad fact that a hot dog that has waited for you to get settled at the table and then been placed in a room-temperature bun (you should be warming your buns, by the way, but this may not always be practical) with cool condiments isn’t very hot by the time it meets your teeth. While a flayed hot dog is subject to faster cooling (nothing a little tin foil won’t fix), it will be hotter off the grill than a round hot dog cooked to the same exterior crispness. This gives you valuable seconds during which you may ketchup/mustard/relish/whatever your hot hot dog to perfection before taking the first bite.
Finally, I don’t know what you’ll decide to be your best grilling dog option, but if you have made a determination in this area without at least considering Hebrew National, I would urge you to reconsider.