Preheat grill to 400ºF.
Use a fork or the “Marinade Turbocharger” to puncture holes all around the potatoes. In a large pot, add potatoes, garlic, onion, bacon, water, vinegar, liquid smoke, sugar, a nice pinch of salt and a few grinds of pepper. Bring to a boil, then lower to a simmer. Cook potatoes until fork-tender all the way through, about 40 minutes.
Remove potatoes to a tray and brush with olive all over. Season skin with salt, then place directly on the grill above the indirect heat. Remove and split down the center with a knife, squeeze ends to open the center and fill with Sweet Bacon and Scallion Dressing.