Whisk mayonnaise, vinegar, Dijon, salt, black pepper, and cayenne together in a bowl until well blended. Whisk in sugar, then stir in celery, bell pepper, carrot, green onions, jalapeño pepper, and poblano pepper. Cover and refrigerate until macaroni is ready.

Bring a large pot of generously salted water to a boil. Cook macaroni in the boiling water, stirring occasionally, until tender but firm to the bite, about 8 minutes. Drain but do not rinse.

Let macaroni drain in a colander for about 5 minutes, shaking out the moisture from time to time. Pour macaroni into a large bowl; toss to separate and let cool to room temperature, 10 to 15 minutes. Macaroni should be sticky.

Pour dressing over macaroni and stir until evenly distributed. Cover and refrigerate until macaroni absorbs the dressing, at least 4 hours or overnight if possible.

Stir salad before serving. Mix water and remaining mayonnaise into salad for a fresher look.