Hi LEW,
Thanks for the kind words in this and the other thread 
Both the Aspen and the Snowmass only have an inch of polyfoam in the top half of the mattress so both of these would be within the guidelines that I generally suggest as being “acceptable”. Foam softening with only an inch of material that will soften more rapidly is not a big issue because of the latex below it (in the case of the Snowmass) or above and below it (in the case of the Aspen). having said that if you are “in between” two choices I would tend towards the one that was slightly firmer and the polyfoam in the Snowmass is quilted which will “pre-compress” it and make it a little more durable (although the latex above the polyfoam in the aspen would also shield it from some of the mechanical wear and add to its inherent durability as well.
You can read a little more about the Seven Comforts shredded latex topper in post #2 here and in post #38 here in this thread (which also talks about another shredded latex topper from Cozy Pure) which can provide some insights about why they can be less “risky” than a solid latex topper in some cases in terms of alignment. At the moment it seems that the Seven comforts is only available on their own site here and only in the king size.
I can tell you I have not noticed any heat issues or temperature increase compared to sleeping on a soft layer of solid latex and because it’s shredded and has a cotton cover I wouldn’t really expect one but because the particles are quite fine and will fill in the voids it could be a little less ventilating than a shredded latex topper with larger pieces.
I use the Natura Deluxe which is one of the protectors listed in post #89 here about the different types of protectors. It’s a wool protector (not thick enough to be called a mattress pad) with a breathable membrane and when I bought it my DH really wanted “waterproof” vs “water resistant”. Even with the wool though the “breathable membrane” can increase temperature vs a protector that doesn’t have the membrane at all and if I was to do it over again I would probably go with the Dormeir because it is also wool, stretchy, and doesn’t have the membrane so the airflow is a little less restricted even though it is not “waterproof” but only “resistant”.
Phoenix