Hi ps99115,
While it’s not possible to “diagnose” mattress comfort issues on a forum with any certainty because there are too many unique unknowns, variables, and complexities involved that can affect how each person sleeps on a mattress in terms of “comfort” and PPP (Posture and alignment, Pressure relief, and your Personal preferences) or any “symptoms” they experience … there is more 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 also 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 identify the types of changes that have the best chance of reducing or eliminating any “symptoms” you are experiencing (at least to the degree that any symptoms are from your mattress rather than the result of any other circumstances or pre-existing issues you may have that aren’t connected to a mattress).
It’s certainly possible that your “symptoms” are coming from some of the other activities that you mentioned but it’s also possible that it could be coming from the mattress as well. The “feeling” that you are sinking in too much or that it “feels like” a trampoline are somewhat subjective (like anything that is described as it “feels like”). They could be “pointing to” layers being too soft for you or they could also be from the natural point elasticity (the ability to contour to the shape of your body) and “feel” of latex (which is a very resilient and “springy” material).
The first step in identifying the types of changes that may be most helpful is to assess whether the symptoms you are experiencing are most likely to come from “comfort” and pressure point issues or are coming from support and alignment issues.
If they are coming from comfort and pressure point issues then changes to the upper layers of the mattress will often be the most effective solution.
If they are coming from support and alignment issues then changes to the deeper layers will often be the most effective solution.
The most common cause of lower back pain is either upper layers that are too thick/soft or deeper layers that are too soft so it would certainly make sense to move firmer layers higher up in your design to “firm up” the support of the mattress and see how that works for you although it’s also possible that there could be other reasons for lower back pain as well.
In most cases the layering and firmness suggestions that are made by more knowledgeable and reliable suppliers would work well “on average” for most people that have a similar body type and sleeping style but not everyone fits inside the averages of other people so there will always be some people that are more “sensitive” that have more difficulty in finding layering combinations that work well for them … especially if you only have 3" layers to work with (since you don’t have the option of doing any “fine tuning” with layer thickness in addition to layer firmness).
Anything is “possible” yes because each person is unique but the only way to know for sure will be based on your own trial and error and personal experience.
I would also work with what you have to find the “best possible” combination before purchasing anything else as well.
Phoenix