In a mixing bowl, whisk together balsamic vinegar, soy sauce, vegetable oil, Worcestershire sauce, maple syrup, brown sugar, onion powder, garlic powder, ground ginger, and red pepper flakes until the sugar dissolves and the mixture is smooth.
Place the steaks in a zip-top bag or shallow dish and pour the marinade over them, turning to coat all sides; seal the bag or cover the dish.
Chill the steaks in the refrigerator for 15–20 minutes to marinate.
Preheat a grill or a cast-iron grill pan over high heat and lightly brush the cooking surface with oil.
Using tongs, transfer the steaks to the preheated grill or pan and cook to your desired doneness, flipping once; check with a meat thermometer: rare <130°F, medium-rare 130°F, medium 135°F, medium-well 150°F, well-done 160°F.
Remove the steaks and let rest for 5 minutes, then garnish with chopped green onions and serve.