Pour oil and corn into a 4-quart pan. Cover with the lid slightly ajar and place over medium heat, lifting and shaking the pan frequently. When the popping slows, remove pan from heat and transfer to a large bowl (big enough for you to get in there and mix).
Add the melted butter, mixing with your hands, spatula, or spoon.
Add the salt and furikake, mixing until evenly distributed. Taste and season to your liking. Keep in mind that nori komi furikake has salt in it, so add the salt in batches, tasting as you go.
Drizzle on the balsamic vinegar/reduction and mix. I like to add 1 tablespoon to start with and then add more if needed.