Hi MW,
I’ll add a “ditto” to Coventry’s comments. I also have the Seven Comforts topper (actually two of them now) and they did have a rubbery smell when they were new which lingered for a while but I didn’t find it in any way offensive. The smell is long gone now. My SO is unbelievably sensitive to unpleasant smells and it also didn’t offend her at all either.
Edit: see post #52 here first if you are considering ordering this topper.
Phoenix