Wasn’t the justification behind not implementing this that it would be really, really easy to generate so much MIDI data that it completely choked your system? MIDI has really, really low bandwidth and even a few dozen simultaneous notes passed to a single physical MIDI port is enough to start causing problems, much less the amount of CC data you would be generating if you could assign controller values to scenes.
I would love to see some of the things that don’t generate MIDI data be assignable to scenes though, stuff like the ARP parameters and the default MIDI note for a track. That would be fantastic. Being able to use scenes to transpose multiple ARPs or change the default notes of a few tracks at once to create chord changes - that stuff would be huge and wouldn’t be affected by the limitations of MIDI.