Hi 70sgirl,
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 (Posture and alignment, Pressure relief, and Personal preferences) 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 experience … hopefully using the testing guidelines in the tutorial post (see mattress firmness/comfort levels in post #2 here).
A firmer layer on top of a softer layer is called a dominating or dominant layer and there are certainly people that prefer it over the more “typical” progressive approach where the softer layers are on top of the firmer layers. There is more about dominating layers in post #33 here and the posts it links to.
If the specs you listed are correct then the mattress is latex from top to bottom (blended Talalay with the exception of the top Dunlop layer) which is a very durable material and there are no lower quality materials or weak links in the mattress.
Some of the layers are in a softer ILD range and given your weights I would make sure that you do some careful testing for PPP (using the testing guidelines in the tutorial) especially to make sure that the mattress isn’t too soft for you and that you are both in good alignment in all your sleeping positions.
Phoenix