Waystone sustainability

Hi,
I’ve cleared 100% of monsters from 3 XV maps and not a single waystone dropped :/ Why?! Two of them were even magic.
From lower-tier maps I did get some waystones.
Can Doryani sell unsold waystones again when you level up or complete higher-tier maps? I didn’t have enough gold to buy all of them before, so most are gone. I’d gladly buy them now that I have some gold (though still not much). He should just add new waystones while keeping the old ones available.

Kill some monsters in act 4 areas. Regal your waystones to rare, and save your best waystones for boss nodes on the atlas.