Another thing to look out for, is choosing a too soft foam for a too small
case, for the mount. A proper design, by a case design company, will take into
the account not only the weight of the mount section, but also the cross
section of the surface area bearing into the foam. As well, they would select
the proper foam modulus, that will "decelerate" the mount before it crushes
enough foam, to stop it before it collides with the hard inside of the case.
Too many people take such things for granted, and put in any kind of foam
so the mount won't get "scratched", never mind damaged. Others, put in far too
much foam, which stops the mount hard in it's tracks - not much better than
simply filling the case with velour covered concrete! Making moulded foam for
instrument cases requires engineering knowledge, or at least a pretty good
grade in high school physics.