Stir together 1/4 cup soy, 1 tbsp peanut oil, half the Sichuan peppercorns, black pepper, honey, toasted sesame oil, 2/3 of the minced garlic, scallions, ginger, and pinch of salt in a bowl.
Add chicken wings and toss to coat. Cover and refrigerate at least 4 hours or up to overnight.
Heat a charcoal grill or set a gas grill to high. When hot, bank coals or turn off burner on one side.
While grill is heating up, remove chicken from marinade and working in batches, thread 2 wings lengthwise onto a skewer and set aside.
Strain marinade into a 1 qt saucepan, discarding solids, Bring to a boil and remove from heat. Brush chicken with remaining peanut oil, and season with salt and pepper.
Grill wings on hottest part of grill, brushing often with marinade and turning as needed, until charred in spots and cooked through (12-15 minutes). If outside starts to burn before wings are cooked, move to cooler section of grill until done.
Whisk remaining soy, peppercorns, and garlic, plus vinegar and hot sesame chile oil in a bowl and drizzle over wings on serving platter.