Those platforms look quite awesome and strong. I'm very happy to see other home grown solutions to the platform material question.
My team also went with a very similar solution to the platform issue originally. I think we used the same foam as you(or something very similar) but instead of aluminum we used fiberglass G10 sheets and epoxied them on. The panels were basically indestructable unless you dug away at the foam insides or point loaded all the way on a corner. However we realized that we'd actually over the course of the construction process slowly made them heavier until they weighed more than aluminum honeycomb. So during our first two competitions we've migrated all of our foam-fiberglass panels to aluminum honeycomb panels. Its unfortunate but it was the only way to make weight and keep all of our functionality. The learning experience remains though. A bunch of members on the team now know way more than they probably ever thought they would about working with foam, industrial scale epoxy operations(don't fill a cup with a tiny bit of epoxy and a whoooole lot of accelerator
) and the properties of fiberglass.
That being said i'm really happy you've had great success with your composite. Its truly amazing stuff.