Hi KinFol,
You certainly are having somewhat of an “ordeal” and hopefully you will soon find a good solution for both of you.
Before considering doing any business with Foam By Mail (FBM) I would read post #2 here and post #2 here.
The pamper has 2" of soft latex (21 ILD) over firmer latex so the thinness of the layer is what creates its firmness. Because there is 2" on top though … the Seven Comforts may be OK. It’s somewhat “in between” a shredded latex topper or even a memory foam topper and a solid latex layer and it would “allow” your shoulders to sink in a little more than a solid topper (that’s what I meant by point specific pressure relief because it would allow the “bony prominences” to sink in a little more than a solid topper). My daughter used it to “camp” on the floor for a couple of nights and said it was surprisingly comfortable for a 2" topper.
Edit: see post #52 here if you are considering ordering this topper.
As you mentioned … ILD has only minor relevance with memory foam because it responds to pressure, temperature, humidity, and time and all of these can change its ILD. in most cases ILD with memory foam in in the range of around 10 to about 15 which would all be considered soft by the standards of other foam but this can be very misleading because like other viscous materials if you impress them or 'slap" them quickly they are firm but if you press in slowly or if they are warned up they are much softer.
Phoenix