Well the transcript is out and Philip Shen got us the answers to our questions. The extra revenue was from Chonqing inventory sell-off of non-poly crap like ingots and poly-blocks. They seemed to have sold off everything so 2019 will be clean. And the subsidies are basically tax returns which will continue to varying degrees over the next years always in Q4.
They also give some good info on production mix and prices which will help to pinpoint EPS over the next quarters I think: https://seekingalpha.com/article/4248446-daqo-new-energy-corp-dq-ceo-longgen-zhang-q4-2018-results-earnings-call-transcript?part=single