Trim and cut the wax beans into thirds. Boil 1 inch of water in a large pot with a steamer basket. Add the beans and edamame, cover, and steam 5 minutes. Drain, rinse with cold water, and drain again.
Toss the steamed edamame, beans, green onions, tomatoes, and basil in a large bowl.
Mix the vinegar, lime juice, honey, and mustard in a small bowl. Whisk in the olive oil. Drizzle over the vegetables, tossing to coat. Add salt and pepper. Serve chilled or at room temperature.
