Hi megan,
There is no such thing as the ILD of a bed or mattress (so of course no manufacturer could provide this) and only individual foam layers are rated in ILD (or IFD). In addition to this … the ILD of individual polyfoam layers would have no meaning for 99% of people because it is only one of many variables that is part of the design of a mattress and will affect how soft, supportive, or suitable a mattress may be in terms of PPP (see post #4 here and post #2 here). Polyfoam ILD’s also can’t be compared to the ILD’s for other materials such as memory foam or latex (see post #6 here).
They are being very wise to not disclose specs that either don’t exist or that for the vast majority of people will likely lead them to believe that they can predict more about how a mattress may “feel” than they can and which would likely cause more confusion and be more misleading to people who don’t have enough experience and knowledge to “translate them” into something meaningful than they would be helpful.
The specs that are important to know are the quality specs of a mattress (not the comfort specs which aren’t useful unless you have a specific frame of reference with the same materials and layers that are comparable) so that any apples to apples comparisons you make can include the quality of the materials.
Phoenix