Hi arndis,
Thanks for taking the time once again to share such detailed comments and feedback. I think it will be very helpful to others in the Ottawa area.
I think you may have meant to link to the Albizia Mattress here (your link led to the Matelaslanpensee website).
ADMIN NOTE:Removed 404 page link | Archived Footprint: Albizia mattress | Matelas Dauphin
It’s likely that this is the bioplush foam in your mattress and is made by Valle Foam (see here). It is a version of polyfoam that has replaced a small percentage of one of the two main petrochemicals that are used to make conventional polyfoam (the polyol) with a polyol that is derived from soy oil. There is more about “soy foams” in post #2 here. If this layer is more than “about an inch or so” thick then like any polyfoam layer I would want to know the density of the polyfoam to confirm that it wouldn’t be a weak link in the mattress.
Other than this … you did some very good research … and congratulations on your new mattress
Phoenix