Cook the potatoes: Bring a large pot of salted water to a boil. Add the potatoes and cook until tender-crisp, about 15-20 minutes. Drain and let cool slightly.
Make the dressing: In a large bowl, whisk together the vegan mayonnaise, red onion, cilantro, dill, lime juice, paprika, cumin, garlic powder, onion powder, cayenne pepper (if using), and chipotle peppers. Season with salt and pepper to taste.
Combine and season: Add the cooled potatoes to the dressing and gently toss to coat. Adjust seasoning with salt and pepper if needed.
Optional add-ins: If using, stir in any of the optional ingredients like bell pepper, celery, vegan ham, or additional herbs.
Chill and serve: Cover the bowl and refrigerate for at least 1 hour to allow the flavors to meld. Serve chilled or at room temperature, garnished with extra cilantro (optional).