Hi sleepTampa,
Post #2 here includes some links to some of the pages on the site that discuss how different body types and sleeping positions need different designs (including the page you’ve read already) and also has my thoughts about using them as a way to choose a mattress.
They are just generic suggestions that can help people understand some of the theory involved in mattress design and act as a starting point but there are too many unknowns, variables, and individual preferences to use them as a specific guideline for any particular person. Your own personal testing for PPP (Posture and alignment, Pressure relief, and Personal preferences) using the testing guidelines in post #1 here as a reference point along with more detailed discussions with a manufacturer if you need to make any custom adjustments (they know more about their mattresses and the materials they use than anyone) is a much more reliable way to choose a mattress that is the best match for your specific needs and preferences.
Of course it’s always important to make sure you know the specifics of all the layers so that you can make sure that a mattress that is a good match for you has no obvious weak links and good quality durable materials and so you can make meaningful comparisons with other mattresses.
If you’ve spent a few hours on the site then it’s quite likely that you know more meaningful information about mattresses and materials than most of the salespeople that sell them … at least in the mainstream part of the industry 
Phoenix