Hi dn,
Absolutely it would make a difference … but the question is how much and whether the difference would be enough.
Post #8 here and the posts it links to has some suggestions for adding a topper which you may find helpful.
Wool will give you some more “point specific” pressure relief under pressure points but it will generally be firmer, spread your body weight over a smaller area, and have a very different “feel” than a foam topper. Of course it will also have a beneficial effect in regulating sleeping temperature.
Your shoulder / numbness issues could also be pillow related because when you add such a thick soft topper to your mattress the distance between your head and the mattress will change which means your pillow may need to change as well because normally adding a thicker softer layer on top would increase pressure relief not diminish it.
3" of any material would change the feel and performance of your mattress significantly and if your mattress was already very close to what you needed and preferred based on your testing then you probably only need some fine tuning and 3" is probably more than you need both in terms of its thickness and its softness.
@ dn,
Thanks for sharing your thoughts about the wool topper you ordered. Your comments reflect the conversations I had with some of the manufacturers of wool toppers that I listed in the wool topper post and I’m looking forward to hearing your feedback on the topper when you receive it.
Wool is less resilient than foam (depending on how it’s made and tufted and the density of the wool to some degree) so there is less risk of alignment issues caused by “allowing” one part of your body to sink in too far relative to the rest.
Phoenix