Hello; I did a simple search on “ foam stand warranty” on this site. Many threads came up. Here are three links out of the many. There may be sort of a consensus about rimmed tanks not needing foam. Some flat bottom tanks can apparently use foam according to some. It also seems that some manufactures require a foam layer and others will void a warranty if foam is used. May I suggest that you gather enough information to satisfy yourself.
http://www.monsterfishkeepers.com/forums/threads/styrofoam-under-a-180-glass.382636/#post-4761201
http://www.monsterfishkeepers.com/forums/threads/new-glass-tank-build.605848/#post-7122471
http://www.monsterfishkeepers.com/forums/threads/busted-aquarium-what-a-mess.424295/#post-5216026
http://www.monsterfishkeepers.com/forums/threads/styrofoam-under-a-180-glass.382636/#post-4761201
http://www.monsterfishkeepers.com/forums/threads/new-glass-tank-build.605848/#post-7122471
http://www.monsterfishkeepers.com/forums/threads/busted-aquarium-what-a-mess.424295/#post-5216026