It can send data, but the faders send sysex, rather than MIDI CC data.
Has your friend considered a straight 88-note controller keyboard?
Arturia Keylabs, Roland A-series, Native Instruments KK, Akai MPK88, etc?
In the 73/76 range, I can only think of the StudioLogic and Numa boards that have weighted actions. Most keyboards in this size are more home-oriented, so lack hammer action keybeds and/or front panel controls.
Away from the new keyboard angle....is the idea of a controller that sits on top of the VR730 a viable consideration?
There are lots of tiny controllers (fader/knob boxes...rather than mini keyboards - although these can also be a good option) that might provide the desired "knobby or fader control" features for MS.
Korg Nano units, Novation Launch Control, etc.
You could also use an iPad for this - but I'd imagine your friend would want something tactile/use by feel alone during live performance - rather than something they need to look at to use.