Just a suggestion but try swapping the lettuce in the tacos for shredded cabbage or coleslaw mix. You still get the same cool crunch but it doesn’t get soggy. Also, more tacos!
Or make them Asian Tacos using seared ahi tuna and shredded cabbage in a soy/ginger sauce!
Black bean and mango salad: beans, mangos, a bit of chopped red onion, cilantro, and a dollop of vegetable oil.