Heat a pot of salted water to boiling then cook the macaroni to tender, drain and set aside.
Cook the chicken any way that you like, steamed, boiled, oven baked. If boiling, and you have the time, add trinity and make some broth while you are at, also, let the pot cool to cool temp before taking the chicken out, this will result in juicy chicken. A Shortcut is listed in Recipe Notes to follow if you want to use a pressure cooker and make broth for another recipe.
Drain the pickle relish and the pineapple, this is so you do not make a soggy salad, no one likes a soggy salad ;)
After everything is cooked, drained, chopped, and cooled, place everything, except the mayo, in a large mixing bowl and gently toss to mix. I started with a mixing bowl, and I lightly mix as each item is prepared and added, I had to transfer to a large pot, as this is a lot of salad.
Add the mayo and gently mix to make sure everything is coated well. Cover and place in the fridge to chill until serving, chill for about 2-3 hours.
Serve as a side dish with chicken from the BBQ, grilled sausages, etc. Or serve as a meal itself.