Put pork chops on a plate; drizzle with oil; season generously with salt and pepper; let sit for 30 minutes.
Meanwhile, build a medium-hot fire in a charcoal grill or heat a gas grill to medium-high heat. Combine vinegar and honey in a 1-qt. saucepan and cook over medium heat until reduced to 1/4 cup. Stir in butter and rosemary and set aside.
Put pork chops on grill and cook, occasionally turning and basting with balsamic mixture, until browned and cooked through, 12–14 minutes. Transfer to a platter and let sit for 5 minutes before serving.