Refurb and non-refurbs coupled

Ahh - but it is one of the only chances you'll get to see a refurb and a non-refurb coupled together
As to the electrical connections, that would not be a problem anyway, as Presspahns were used to insulate the connections.
And as to 'they' were doing pushout tests - more 'we' were simulating push-outs for new drivers ;D ;D

Yeah, it does.

I was kinda hoping that someone would couple a refurb UNDM to an unrefurb UNDM, just to see what would happen

I think that the refurb D stock would look better if they painted the half window behind the cab black.