Hi Mahe67,
The first place I would start if you have any questions or issues with a mattress you purchased (either in terms of your comfort or the mattress itself) is the manufacturer or retailer themselves. They know more about their own mattresses and what may be necessary to deal with any “symptoms” you have than anyone else. The better manufacturers such as Cozy Pure generally treat you as a customer for life and will continue to give you good information and advice long after your original mattress purchase.
Post #2 here also has some suggestions that may be helpful.
Your experience is somewhat difficult to “interpret” because it goes against 'theory" to some extent so it would involve more time and some detective work to identify the cause behind your experiences and this normally takes more detailed conversations on the phone. It could also involve an adjustment from a “learned” sleeping position where you have “adapted” to a mattress that doesn’t provide good alignment and there can be some “symptoms” involved when you change your sleeping surface and it provides better alignment. There is more about “learned alignment” in post #7 here.
I don’t know any details about your or your body type but in general the performance plush would make a good choice for people who sleep on their side or in multiple sleeping positions and needed a softer sleeping surface. Both the zoning and the type of material (Dunlop latex) can be a make a good choice in terms of alignment in multiple sleeping positions but of course each person is very individual in terms of the specifics of their body type, sleeping positions, and how they interact with any specific mattress.
This is the part that “contradicts” theory and would require some more detailed detective work on the phone or in person to identify why you are experiencing something unusual. In most cases a mattress that works well for a side sleeper would easily be soft enough for a back or stomach sleeper (and sometimes too soft). If anything back and side sleeping generally needs a thinner/firmer sleeping surface than side sleeping.
If your chest is feeling like it is being “pushed up” this may indicate that the area under your pelvis is a little too soft so your upper torso “feels” higher relative to your pelvis. In general the same areas that need to be firmer (under the pelvis) with side sleeping also need to be firmer with back and stomach sleeping because the area of greatest weight is the same. Your “symptoms” could also be connected to a pillow issue which can effect upper body alignment. If the mattress is soft enough for your shoulders on your side then it would also normally be soft enough for your mid and upper torso when you are on your back or stomach although the details and specifics of the zoning may also play a role here. My guess is that the issue may be connected to how deeply you are sinking in with your pelvis more than it is connected to the firmness of the latex under your mid or upper back.
Before you make any changes it is important to identify the root cause of any symptoms you are having. Making the wrong change of changing the design for the wrong reasons can sometimes make any issues worse or introduce new issues. the lanoodles is a good choice for some extra softness on top because the design would have less effect on alignment but first I would want to have a clearer picture of why you are experiencing what you are experiencing.
The most important thing you can do is to talk with Hans or Cheryl to use their knowledge and experience to help you identify the underlying cause behind what your “symptoms” and once you have a clearer picture of “why” then you will be in a much better position to identify the types of changes that would deal with your symptoms most effectively. If the underlying issue is that you need more surface softness then a topper such as the lanoodles can be very effective but if the underlying issue is that the upper layers are already too thick or soft then a topper is not generally an effective solution.
Phoenix