Last month I had reasonably good results using the Omegon binoviewers with a SW180 Mak, with no OCS/barlow/amplifier (hereby called OCS for short). I say "reasonably good", because the views are restricted to relatively high magnifications, dictated primarily by the long focal length of the SW180, and my desire for BVing is mostly for low-mag, wider-field views.
So now I'll try to get the BV-sans-OCS to work with the ES ED127. The difference in focal length (950mm vs 2700mm) should give a threefold improvement in field width.
This pic shows the baseline setup, the one used for mono-viewing: A 37mm extension tube; the 2" eyepiece holder; a 2" diagonal; and a 1.25" adapter.