Hi Matt ress,
While I don’t know for certain the reasons behind comments made on a phone call that I wasn’t part of … I would suspect that your comment here is probably accurate.
From the perspective of the quality of the materials … it would certainly be suitable for an adult.
My first step would always be a phone call with the manufacturer who will tend to be more familiar with the options that are available that have worked for others in a similar situation than anyone else
Reversing the layers would certainly be worthwhile testing as a pointer although I’m not quite sure if I’m understanding you correctly about the specifics. I would differentiate between the softer comfort layers (which are more for pressure relief) and the firmer support layers (which are more for support). The base layer for the medium model appears to be the C5 which is the firmest layer they make (although this would depend on which set of Mountaintop’s ILD numbers the 34 ILD refers to) and I would tend to keep the firmer base layer in the medium as it is (again assuming it’s C5). I would tend to use a comfort layer that was softer than the base layer because a C5 comfort layer may be too firm for most people (although of course there may be some that prefer this and if the C4 is too soft as a comfort layer then there is only one firmer option available)
If you flip a convoluted layer upside down with the convoluting on the bottom it will also tend to be a little firmer than with the convoluting up so it can be worthwhile flipping either the comfort layer, the support layer, or both individually to see if this makes a difference.
There is also a difference between how far you sink into a mattress and how evenly you sink into a mattress. How far you sink into a mattress is more of a preference and affects the more subjective perceptions of “comfort” and “feel”. How evenly you sink into a mattress is more of a “need” and affects spinal alignment (see post #6 here). When you are assessing a mattress in terms of PPP, it’s always a good idea to differentiate the sensations and symptoms that are likely connected to the two basic “needs” (Posture and alignment and Pressure relief) which are the first two “P’s” and are more objective than the sensations that are more about “preferences” which is the last “P” and is more about subjective perceptions such as “feel” and “comfort”.
While all of these are not completely independent of each other and every layer will affect the feel and performance of every other layer to some degree … this will help identify and clarify whether any sleeping issues or “symptoms” are more about pressure relief, alignment, or preferences which in turn will help identify the most likely source of any issues and which layer changes have the best odds of correcting any symptoms.
Phoenix