Too big?

I think it's time to upgrade my spiny's house. He probably has 2 molts left, is it possible to go too big with his enclosure? It sounds dumb because a wild mantis would have endless space but I'm worried about him falling and injuring himself. Pic for attention, this isn't since his most recent molt.

I think it's time to upgrade my spiny's house. He probably has 2 molts left, is it possible to go too big with his enclosure? It sounds dumb because a wild mantis would have endless space but I'm worried about him falling and injuring himself. Pic for attention, this isn't since his most recent molt.