I just have a few minutes--faculty in-service today. All I can say is no, Darby did not translate epi like en, he translated it like epi, which has a wide range of meaning, including the meaning which he gave it in this passage.
Here is Friberg on the word:
epi, preposition with a basic meaning on,
Thank you. It's settled then. Revelation says the things in Revelation are on/upon the church, not that the angel is testifying to John in the churches (which make no sense, as the angel testified to John on the Island of Patmos, away from the churches). Darby is wrong.
. with the dative emphasizing position; (1) of place on, in (MK 6.39)[/quot]
Mark 6:39 "sit on/upon the green grass", not "sin in the green grass.", except insofar as "in" means "on". John nor the angel were sitting on top of churches, as one an sin on grass. In Revelation 22:16, the dative does not emphasize position.