I’m wondering who here is a “purist” and only interested in untreated unheated stones
Not about being a purist; it's just the only thing I trust. I feel like the next undetectable treatment will still involve heat (like Be diffusion, etc.) so I jut avoid heat.
I would not get a less attractive unheated stone over a more attractive heated stone, though, if dollars were limiting. In that case, I would just make sure that a top lab affirms it is "heat only." I do not think there is any difference between "high heat" and "low heat."