Reserve ¼ cup of the sliced scallions for later. In a blender or food processor pulse remaining scallions, cilantro, garlic, zests & juices, soy sauce, oil & salt until pureed. Reserve ¼ cup marinade. In a large resealable plastic bag, add chicken and remaining marinade, seal bag, then shake to coat. Chill at least 30 minutes. If using wooden skewers, soak skewers in water while the chicken is marinating (30 minutes).
Preheat grill on medium heat for 20 minutes. Remove chicken from refrigerator and skewer each piece of chicken with 2 skewers. Place chicken skewers evenly across hot grill. After 3 minutes turn each skewer 90°. After another 3 minutes flip skewers over. Turn 90° after 3 minutes, then after another 3 minutes check temperature. Once the chicken thighs reach 165° internal temperature remove from heat, cover to keep warm & let rest a few minutes. While chicken is resting, place the lime wedges on hot grill. Flip after about a minute, then remove from grill after another minute. Serve chicken with grilled lime wedges, reserved scallions & marinade. Enjoy!