Preheat broiler to High with rack 6-inches from the heating element (top of the oven).
Sauté diced bacon in a skillet over medium heat until crisp, 8-10 minutes. Drain on a paper towel-lined plate.
Slice top ⅓ off the baguettes and remove most of the bread inside. Cut the whole baguette into 4 equal portions and the remaining half baguette into 2 portions. Brush each piece with 1 tbsp oil, season with salt and pepper, and broil on a baking sheet until toasted, 2-3 minutes. Watch closely because they burn quickly. I have charred many a baguette by my multi-tasking.
(Full disclosure: I just broil my baguettes without the olive oil and salt and pepper. I also broiled the them before cutting them, though I highly recommend cutting them and then broiling).
Mince cilantro, mint, ginger, and lime juice in a food processor or blender. Add mayonnaise and yogurt; pulse to combine. Season with salt and pepper to taste (maybe ¼-ish tsp?).
Mix chicken, bacon, and nuts with pesto in a bowl and set aside. Toss spinach with 1 tablespoon vinaigrette, if desired; stir pineapple and jalapeño (if using) together in a bowl.
To assemble sandwiches, divide spinach between baguettes, then top each with 1/2 cup chicken salad. Divide pineapple between the sandwiches and garnish with bell pepper.
Whisk lime juice, honey, oil, and a pinch of both salt and pepper together.
For the remaining vinaigrette, you can make a cantaloupe-avocado salad: cut half of a cantaloupe into bite-sized pieces. Slice two avocados into bite-sized chunks. Place in a bowl together, sprinkle with ¼ cup thinly sliced shallots, then drizzle with vinaigrette.