Bottom heavy and bottoming out on organic latex

Just under a year ago we purchased a Sleep Ez Full 10” organic latex mattress, and we have never been able to make it work. I was lighter then, but currently I’m 145lbs, 5’2” tall. My partner is 5’6”, and roughly 150lbs. I am a side/back sleeper, and he is a back/stomach sleeper. The first configuration we received was Soft talalay (top) Medium dunlop (middle) firm dunlop (bottom). After a few weeks trial I found that the initial lower back relief I felt was replaced by a stiff neck because my shoulders weren’t sinking in enough. In fact, I noticed my hips were raised too, as there were minor gaps whether on my back or side. My partner had said he felt stiff in the shoulders at first too, just not as bad as me.

I had them send more foam, so that the middle medium was now talalay, and the bottom was split ½ firm dunlop, ½ medium dunlop. My side hammocked, so I put the firm dunop back on the bottom and got a 2” soft talalay topper, hoping I could return to the original support but with a little more cushion for my shoulders. The hammocking never really went away on my side, in fact both of our sides have broken in significantly, compared to the center which is almost as firm as day one, as the middle medium is still (if I’m not mistaken) talalay instead of dunlop.

Once the trial period ran out, Sleep EZ became less communicative. The last advice they gave me was to take off the mattress covers so all the layers would relax around the edges. So I’m still sleeping in a hammocking uncovered mattress. Admittedly, I’m not an easy body to support, I’m bottom heavy with wide shoulders, and my weight tends to wildly fluctuate. In coil mattresses of the past I would sit at the top of the bed to read until a dent was made that would inadvertently accommodate my shoulders. I remember really enjoying the Casper Wave when I tried it, though my partner was less keen. I considered going with Flobeds instead of Sleep EZ, and wonder if I should call on them to make us a custom layer. Other people on this site have suggested a diy hybrid, adding a shallow coil into the equation. I also have a random 1" medium dunlop topper kicking around, maybe that’s still useful. OK experts, what should I do?