Gomortega keule

Always on the lookout for interesting,rare, edible trees and plants i came across Gomortega keule. It's an endemic chilean tree with edible fruit (supposed to be tasty!)
The tree is very rare and endangered of extinction. Information about it is very hard to find. Seeds are seemingly impossible to obtain.
I would like to know its plant hardiness. Judging from where it grows it seems to be hardy to zone 9 (more or less)

https://www.rarepalmseeds.com/pix/GomKeu.shtml

Anyone know more about it?