Season: The evening before cooking, place pork shoulder on a sheet tray, trim the pork shoulder of excess fat. Coat with Dijon mustard, and the dry rub liberally. Cover with foil or plastic wrap, and place in fridge.
Smoke: The next day, preheat the smoker to 250 degrees Fahrenheit and remove the pork from the fridge and uncover the meat. When smoker comes to temperature, place pork, unwrapped, onto the smoker. Insert a probe thermometer if you have one.
Spritz: Smoke for 3 hours. After 3 hours spritz with apple cider vinegar each additional hour, until the internal temperature of the meat reaches 165 degrees F (approximately 3 or 4 additional hours). At 165 degrees, remove any thermometer and set aside.
Wrap: Place pork shoulder into a large oven safe tray (or a 9x13 glass baking dish). Add remaining spritz liquid into the bottom of the tray, and then cover with foil. Insert meat thermometer back into the pork shoulder for monitoring if using one.
Smoke: Continue cooking, covered, another 3 to 4 hours until the internal temperature of the pork reaches 200 degrees F. When the internal temperature reaches 200 degrees begin inserting an instant read thermometer into several places. It is done when the probe inserts like butter (and the temperature reads between 200 and 205 degrees).
Rest: Remove from smoker and let sit, covered, for at least 30 minutes (ideally 60). Then remove the bone and pull the meat, discarding any remaining fat or cartilage.
Serve: For sliders on a bun, place the pulled pork, then the grilled pineapple slaw (recipe in notes), then drizzle a small amount of reserved savory soy and balsamic sauce.