Hi domaignew,
I don’t think that knowing the ILD/IFD of the individual layers in the 12 in 1 would really have any “real life” meaning to you anyway because with polyfoam ILD/IFD is only one of several specs that affect how soft or firm a polyfoam layer will feel (see post #4 here) and it also doesn’t compare to the ILD/IFD of other types of foam like latex or even other types of polyfoam (the same ILD in both would have different firmness levels) so it really wouldn’t tell you anything about how soft or firm any of the individual layers or any of the layer combinations will feel to you anyway.
These are specs that would only have meaning to someone that was very experienced with many different types of foam materials and familiar with what they mean or “feel like” in their own actual “real life” experience and it’s much simpler to make your choices based on more detailed conversations with a knowledgeable retailer or manufacturer who can describe their mattresses in ways that would make more sense to you rather than using specs that have little meaning by themselves.
There is more about the different ways to make the most suitable mattress choice (either locally or online) and how to identify and minimize the risks involved with each of them in post #2 here and trying to make your firmness choice based on these types of specs will probably do more to confuse you than to help and would be among the least reliable and most risky ways to choose a mattress.
Phoenix