Make the aji panca puree: Put the aji panca chiles in a large bowl and cover with 1 1/2 cups boiling water. Cover with plastic wrap; let soak at least 1 hour or overnight.
Puree the chiles and their soaking liquid with 1 teaspoon salt in a high-powered blender. You should have 2 cups; remove 1 1/2 cups and reserve.
Make the marinade: Add the olive oil to the remaining puree in the blender along with the vinegar, tamari, gochujang, garlic, cumin, oregano and 1/8 teaspoon pepper. Season the chicken with salt and toss with the marinade in a large bowl; let sit 10 minutes.
Meanwhile, make the serrano-cilantro sauce: Blend the serranos, poblano, cilantro, lime juice, orange juice, olive oil, mayonnaise and 1 teaspoon salt in a blender until mostly smooth. Set aside.
Preheat a grill to medium high. Thread 4 or 5 pieces of chicken skin-side up onto each of 10 wooden skewers, leaving space between each piece. Grill the chicken skewers skin-side down until marked, about 3 minutes. Flip and cook until charred and cooked through, 3 to 4 more minutes.
Transfer the skewers to plates and top with some of the reserved aji panca puree and the serrano-cilantro sauce. Sprinkle with cilantro and peanuts.