Dan,
Thank you for trying. You beat me to that video, but that is a workaround, since you are essentially copying EZkeys MIDI to another track. Not routing MIDI signal.
Yes, it works, however the downside is that with every Chord sheet change (or EZkeys timeline change) the process has to be repeated.

If on the other hand there is a clean cut way to link EZkeys MIDI out to MIDI in of another VST synth, it will eliminate all dragging around. It will just duplicate whatever EZkeys is playing.

Looking forward to 2024 when BIAB will adopt to VST3 and as I understood EZkeys 2.0 will allow for live chord input... That MIDI through would be very handy.

Maybe the routing is possible at this time? If not, I believe it will be a very good candidate for a feature. Not specifically for EZkeys, but for all MIDI based VSTs that do not have sound source too.