Preheat grill to medium high heat. Place corn and poblano directly on the grill and cook, turning occasionally, until the pepper and corn have browned bits. Remove and let cool before cutting kernels off of cobs. When pepper is cool enough to handle, discard the seeds and stem, and dice into small pieces.
Whisk together olive oil, lime juice, apple cider vinegar, salt, pepper, and paprika. Set aside.
In a large bowl, combine corn, poblano, tomatoes, cilantro, onions, and feta. Stir to combine. Pour dressing over salad and add avocado cubes. Gently stir and serve immediately or refrigerate, saving avocado until just before serving.