I live in Florida in a very hot and humid older home, condensation is an issue for sure. I still prefer all my cakes to be refrigerated because it makes delivery more safe. I do put dry ice in my delivery box to keep the cake condensation free and usually the places the cakes go to are not as humid inside as my house, any condensation does dry up but yes it can leave small pit marks on your buttercream and fondant. Very small. Probably no one but the decorator would even notice. It’s part of living in the heat and if anyone ever questions it just explain that. It’s a scientific fact that can’t be avoided completely.