G70 can send any Part (keyboard, Style or SMF) out to MIDI, but it has one serious flaw... From the registration it can only send CC0/32/PC# to the Style or SMF Parts. There is no way to program the Keyboard Parts to send any CC00/32/PC# directly from the Tone selection buttons.

There IS a workaround, where you program a sequence to send out the codes for you, but it lacks the immediacy of being able to call up an external sound from the front panel. MAYBE Roland will address this (pun intended!), but just lately I have the impression that the arranger R&D guys are asleep at the wheel when it comes to using their arrangers with ANY other gear, whether modules or even a computer sequencer.

The old G1000 was 200% better at talking to a computer sequencer, although no better at addressing external gear from the front panel...

But at least it CAN be done on the G70/E80/60/50, if only by preparing things in advance...