Wrap the tofu in a clean towel and press it beneath a weighted plate for 15 to 20 minutes. Cut into 1 1/4-inch cubes.
Whisk the tomato paste, tamari, maple syrup, lime juice, apple cider vinegar, oil, smoked paprika, garlic, ginger, and black pepper until smooth. Transfer one-third to a clean bowl and reserve it for serving.
Combine the tofu, pineapple, bell pepper, zucchini, and red onion in a large bowl. Add half of the grilling portion of glaze and fold gently to coat. Rest for 10 to 15 minutes.
Heat the grill to medium, about 375°F to 400°F (190°C to 205°C). Clean and lightly oil the grates.
Alternate the tofu, pineapple, bell pepper, zucchini, and red onion on six skewers. Leave a little space between pieces for even cooking.
Grill for 10 to 12 minutes, turning every 3 minutes, until the tofu and vegetables have clear grill marks and the pineapple is caramelized.
Brush with the remaining grilling glaze during the final 3 to 4 minutes. Turn as needed so the glaze caramelizes without burning.
Rest the skewers for 2 minutes, then brush with the clean reserved glaze. Serve with lime wedges and optional cilantro or green onions.