Cook the pasta: Bring a large pot of salted water to a boil. Cook macaroni until just al dente. Drain and rinse under cold water to stop cooking and cool it down.
Dress the chicken: In a bowl, toss the cooked chicken with 1/4 cup of the BBQ sauce.
Set aside so it soaks up the flavor.
Make the dressing: In a large mixing bowl, whisk together mayonnaise, Greek yogurt (or sour cream), remaining 1/4 cup BBQ sauce, apple cider vinegar, Dijon, honey, smoked paprika, garlic powder, a good pinch of salt, and a few cracks of black pepper.
Add the mix-ins: Stir in red onion, celery, red bell pepper, corn, pickles or relish (if using), and cheddar (if using). Fold in the sauced chicken.
Toss with pasta: Add the cooled macaroni to the bowl. Gently toss until everything is coated and evenly distributed.
Taste and adjust: Add more salt, pepper, or a splash of vinegar if it needs brightness.
If it’s too thick, loosen with a tablespoon of water or milk.
Chill: Cover and refrigerate for at least 30 minutes, preferably 1–2 hours, to let the flavors meld.
Finish and serve: Before serving, give it a stir and top with green onions and fresh herbs. Serve in bowls as a main or side.