I don't know if they changed the frustrating spawn rate of the spirit stone RNG layers in 2.0 to make it easier, but if they haven't, I have a game session currently open with a spirit stone available. Non-HC (figures, the one character that isn't HC finds it), feel free to ask for an invite, Fhi#1854.
Only one person can buy it though. I'll leave the game open for a bit.
Haha that achievement haunted me until 2.0 then it finally spawned the first night! I don't know if I got lucky or if the RNG gods smiled down upon me with a legendary merchant