Place a large pot over medium-high heat with the four reserved corn cobs, celery leaves, water and chicken stock. Bring liquid up to a bubble and reduce heat to medium-low. Simmer and reduce broth until about 1 1/2 cups remain, about 10 minutes. Keep warm until use.
While broth is simmering, place a heavy-bottomed pot over medium-low heat with 1 turn of the pan of EVOO, about 1 tablespoon. Cook the bacon until crisp and brown, 4-5 minutes. Remove bacon from pot with a slotted spoon and drain on a paper towel-lined plate.
Pour off all but 2 tablespoons of the drippings from the pot and add the potato, onion, garlic, celery, red pepper, bay leaves, thyme sprigs and corn kernels to the pot. Saut over medium-high heat until vegetables begin to soften, about 5 minutes. Add milk, hot sauce and corn broth and bring to a bubble. Reduce heat to medium-low, and simmer chowder until potatoes are tender, about 15 minutes.
If using crab, place into a small bowl and toss with Old Bay seasoning. Serve chowder garnished with crab, a pinch of scallions and some of the crispy bacon.