Wow a mix for a lime cake! That sounds good. If I had such mix I would bake it in a 13x9x2 pan or a jelly roll pan (I do that a lot for cakes these day so I can cut into small pieces). I would make a topping of thinly sliced kiwi and sliced fresh strawberries. I would first put a thin layer of a strawberry glaze (homemade like for a fresh strawberry pie--but store bought jarred might work) then I would arrange the fruit on top of the glazed cake. On top the stawberry glaze so the fruit was shiny but colorful. I have done a lime chiffon pie made in a springform pan with this topping many times. It is beautiful and I love the flavors together.
I hope this helps...Sue