Hi micmse,
Do you have the SleepEZ organic, the natural, or the special (without the wool quilted cover)?
Not surprisingly … I would agree with all of this
It would depend more on the firmness of the layer than on the which type of latex that you use but firm Talalay layers (or latex of any type) are very supportive yes and there are many people in much higher weight ranges than you are (300 or 400 lbs) that do very well with Talalay and prefer it over Dunlop support layers (and of course other people may have the opposite preferences). It’s really a preference choice.
Dunlop tends to get firmer faster as you compress it so changing the layers in the middle of the mattress to a Talalay layer in the same ILD would probably also help somewhat with pressure relief. Of course an additional topper so you have a similar setup to the Savvy Rest you tried and liked (or even something like F/M/M with a soft topper) would also be softer than a 3 layer configuration that has a single medium layer in the middle because additional thickness can also add additional softness (see post #14 here).
With the temperature issues … if you have one of the membrane type of mattress protectors then this can often increase sleeping temperature for some people as well because it’s less breathable than some of the other types of mattress protectors. There is more about different types of mattress protectors in post #89 here.
I would tend to make small and incremental “one step at a time” changes and make sure you sleep on each new configuration for at least a few days so your body has a chance to catch up to the new layering and you can identify a pattern (one or two nights experience can sometimes be an anomaly) and then use the difference in your experience and symptoms (whether the symptoms seemed to improve or worsen) between each new combination and the last one as a “pointer” for the direction of any additional changes that you may need.
Phoenix