Hello! I guess this is a bug report.
So I usually use raidbots and AMR combined with each other. I was simming a 915 Engine of Eradication v. a 935 Astral Alchemist Stone. Raidbots told me the alchemist stone was about an 8k upgrade. AMR, however, simmed it as a 60k dps loss. I thought this was weird, asked around, then noticed that AMR isn't including the alchemist stone's buff.
Here's a link to the simulation through AMR with it equipped: http://www.askmrrobot.com/wow/simulator/report/fecaf630d378479bb9b08aa473aa9d45
Here's a link to the simc report: https://www.raidbots.com/reports/7zDNygLoLEu66Bkxns9cxy/index.html .
It looks like there should be an "infernal alchemist stone" buff with an upkeep of about 25-ish%. Without that buff it's probably why there's such a huge disparity. not sure this is something y'all are already looking into, but figured I should report it anyway just in case someone else is confused.