I was in the Revelation training in December of 1976 and the partial rapture was discussed. The rapture is a harvest and according to Lee, not all grain matures at the same time. You have the firstfruits, general harvest, and gleanings. Mature Christians will go in the first rapture as the firstfruits. Of course the LC is the best place to grow into a mature Christian according to Lee,
although it would be possible elsewhere. Others Christians would have to go through a part of the tribulation, and would go in the general harvest, the 2nd rapture. The least mature would be the gleanings, and not mature until they went through the whole tribulation and Jesus returns. However anyone still not mature would go into outer darkness to mature. My note: Protestant purgatory?!
I can't give you references or notes. I threw away any book s I had that related to the LC, so when I die someone can't find it, read it and be lead astray!