Well, kiss OOB support goodbye with High Sierra 10.13.2.
At least, if you want sleep to work properly. Apparently, only Sapphire RX 580 Pulse in 10.13.2 has sleep function working properly.
My RX460 which has been trouble-free up until 10.13.2 no longer has sleep working.
Sleep bug is... machine goes to sleep either user-initiated or automatically will not go to sleep... display is off, and LED power light on the Mac Pro will glow in and out like it is asleep, but, the thing is still on. Also, can't resume from sleep. So, I have to press and hold power button to turn it off and turn it back on, again.
This makes my cMP basically behave like a hackintosh! Doh!
This is not good news because if this is not fix, it means the marked up price of the already marked up Sapphire RX580 Pulse will get even more marked up.
Not fun.