I have used this stuff in the past - I have a pack with a hipbelt that has a layer of 3/8" Blue-foam and a layer of reticulated that is over 25 years old and has been used on many trips. The reticulated has compressed some, but I would say less than 50%. As to the breathability, I think you'll find that overrated. By the time you cover it with fabric of some kind (I used Leno mesh for maximum breathability) you'll end up sweating about as much as you would with most hipbelts - at least that's my experience. I have not used it since on any of my packs. I suspec tthe main issue is that it is very breathable when not under compression, and less so when compressed - and it compresses quite easily. That belt is still very comfortable, however!
My current solution is to use breathable fabric (uncoated 160d cordura) and perforated 1/4" thick closed -cell foam. Not perfect but I'm pretty happy with that.
I also tried some Brock Foam - supposedly breathable foam that many pack manufacturers were using - but found that it doesn't hold up well.