In a medium saucepan, combine sugar, flour, and salt over medium heat. Gradually stir in the unsweetened pineapple juice and cook, stirring constantly, until the mixture reaches a gentle boil and thickens, about 5-7 minutes. Remove from heat and set aside to cool slightly.

In a separate bowl, beat the large eggs until frothy. Slowly pour a little of the hot pineapple mixture into the eggs while whisking continuously to temper them; this prevents scrambling. Once combined, return the egg mixture to the saucepan and stir for an additional two minutes over low heat. Mix in the fresh lemon juice, then remove from heat to cool completely.

Bring a pot of salted water to a boil, then add the acini di pepe pasta. Cook according to package directions, usually about 6-8 minutes, until al dente. Once cooked, drain the pasta and rinse it under cold water to stop the cooking process. Set the pasta aside to cool completely.

In a large mixing bowl, add the cooled acini di pepe, mandarin oranges, pineapple chunks, crushed pineapple, miniature marshmallows, and sweetened shredded coconut. Gently fold the ingredients together until well mixed.

Once the dressing has cooled to room temperature, fold it into the pasta and fruit mixture, making sure everything is evenly coated. Gently incorporate the thawed frozen whipped topping into the salad.

Cover the bowl with plastic wrap and refrigerate for at least two hours, though letting it sit overnight enhances the flavors even more.

When ready to serve, give the salad a gentle stir and dish it into serving bowls. Garnish each serving with a maraschino cherry on top.