Hi blackriderx,
Unfortunately you are the only one that can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved to use a formula or for anyone to be able to predict or make a specific suggestion or recommendation about which mattress or combination of materials and components would be the best “match” for you in terms of PPP based on specs (either yours or a mattress) or “theory at a distance” that can possibly be more accurate than your own careful testing or personal sleeping experience (see mattress firmness/comfort levels in post #2 here).
Having said that … there is more detailed information about the most common symptoms that people may experience when they sleep on a mattress and the most likely (although not the only) reasons for them in post #2 here.
There is more about primary or “deep” support and secondary or “surface” support and their relationship to firmness and pressure relief and the “roles” of different layers in a mattress in post #2 here and in post #4 here that may also be helpful in clarifying the difference between “support” and “pressure relief” and “feel”.
These posts are the “tools” that can help with the analysis, detective work, or trial and error that may be necessary to help you learn your body’s language and “translate” what your body is trying to tell you so you can make the types of changes or additions to your mattress that have the best chance of reducing or eliminating any “symptoms” you are experiencing.
If you are looking to firm up the feel of the sleeping surface then the changes that you made from (from the top down) from S/M/F to M/S/F would be the most common change that would firm up the upper layers of the mattress.
If you are looking to firm up the primary support of the mattress then changing from S/M/F to S/F/M would be the most common change.
These are the two ways to rearrange the layers that would generally meet the needs and preferences of most people with a 3 layer component system.
There are also some suggestions in post #2 here about a mattress that is too soft that may be helpful as well although most of these (outside of the suggestions about your support system or zoning) wouldn’t apply to a component mattress where the layers can be rearranged or exchanged.
Other than these … the next most likely option would be to replace the soft layer with a medium layer and try various layering configurations without the soft layer. The most likely of these would be M/M/F or M/F/M. If you have split layers then you can also try these on one side of the mattress to see how well it works for each of you and how any symptoms you are experiencing change with firmer configurations.
While it can depend on your weight, sleeping positions, and personal preferences and sensitivities … based on “averages” one of these configurations would generally work very well for the very large majority of people (although there are always a small minority that may be outside the “averages” that would work for most people)…
Phoenix