Peel, pit, and cut avocados into chunks.
Cut bananas in 1-inch-thick diagonal slices.
Mix avocado and bananas with lemon juice.
Remove peel and white membrane from oranges; add sections with pineapple to avocado mixture.
Sprinkle with ginger and cover and chill, if made ahead.
Prepare lime-curry dressing.
Toss fruit gently to mix, sprinkle with macadamias, and garnish with thin lime slices.