Mustardy Grilled Cabbage and Kielbasa

Name: Mustardy Grilled Cabbage and Kielbasa
Ingredients: Vegetable oil (for grill); 1 lb. small red potatoes, halved, quartered if larger; 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt; ½ tsp. garlic powder; ½ tsp. smoked paprika; 4 Tbsp. plus 1 tsp. extra-virgin olive oil, divided; Freshly ground pepper; 1 Tbsp. mayonnaise; 1 Tbsp. Dijon mustard; 3 Tbsp. whole grain mustard, divided; 1 small head of savoy cabbage, cut through core into 2–3-thick wedges; 1 12-oz. kielbasa, quartered crosswise, then halved lengthwise; 3 Tbsp. apple cider vinegar; Torn dill (for serving)