Hi there,
i don't think this has been suggested yet

it would be great to have a secondary master-video preview, on which one could preview the transition by moving the cue fader on the ttm57 or any second horizontal fader on some midi hardware.
that way, you could check on how it looks before actually doing the fade between two videos.
just like the cue functionallity that we all use for prelistening to an audio song, but at the same time for the video part.
the way it is right now, i can pre listen, but i have to guess on how the transition will look on the big screen.
should not be too hard to implement, just another instance of the main out preview, that is linkable independently to the cue fader. ( ? maybe it is hard and im wrong :-) )

you then had four video screens on your internal display instead of three but i think there is enough space.
i think one issue for some users could be the extra cpu usage for a fourth preview, but then they might just not use it.
if it is not clear what i mean, i can make a faked screenshot and up it somewhere.

i think no concurring product has this, be the first, serato!