Thank you Phoenix for responding.
The 3" topper is sitting on a solid wooden box foundation (not a frame), which is about 3/4 inch thick, so it is very similar to placing it on the floor directly. The foam is softening under heavy parts of the bodies. When looking at the topper, the sag is not easily detectable. I cannot see more than 1" of permanent depressions.
When my husband rolled around on the topper, he could feel that the center part of the mattress is firmer than where we normally sleep on. We tried rotating the mattress 180 degrees because the softened area is asymmetrical length wise. He noticed a slight improvement at first couple of nights, but I didn’t notice any difference.
We have not tried flipping the topper, because the top side has bamboo cover, and the bottom side is a stronger paper towel type material. He thinks flipping it would not make a difference, although I understand that stiffer paper cover may slightly resist the stretching of the surface.
We know we want to go firmer than 28 ILD, and 100% NR. 2" or 3" 44 ILD NR Dunlop seems commonly available so we will search in the online store list here. Do you think that’s a good approach?
Of course 28 to 44 ILD is a big jump so checking out the feel of that range in person at a store before ordering would be ideal. We are currently in AZ, a couple of hours drive to Yuma. Actually we are going to be there tomorrow. If you are aware of a good store to check out in Yuma, please let me know.
Thank you.