Jermyn,
I returned from a short-term missions trip 4 years ago with Logos Communications, international and stayed at their conference center in Chiang Mai. LCI was chaired by Wayne Nigh, an ex-pat UPCI one-stepper.
My Thai translators told me that David Bernard has personally told their churches in Thailand to NOT have fellowship with LCI.
It isn't over sin or moral issues but over control and deep-seated belief that one-step isn't "enough". I wrote DKB when I returned home and queried him about it. I'm still waiting for a reply.
Of course it should have been done a long time ago. In my mind the purists have deconstructed the power of unity of the Oneness movement with their obstinate superior attitudes (eg: Why haven't they joined the AWCF?). The hate I experienced while a member of the Oregon District (and one with a history with Nigh and Cobb) has not changed. Present-day Pentecostals have NO idea that there was a fault line between the two groups. You can't find this information in their bible colleges; in fact they have redacted/whitewashed references to Conqueror's Bible College in Portland, a school with a suspected 1 step emphasis. It was re-named Cascade Bible College and moved from its long-time home in Portland due to purist opposition.
The purists' idea of "holding forth the word of truth" doesn't consider their position to be in violation of Jesus' prayer for unity in
John 17.