Yeah, actually, he said he tried putting an controller output jack on the Turbo Express, which would make the RGB out mod a bit more practical - that way, you basically have THE smallest PCE system that you can connect to your TV. That was his first intention, but unfortunately, the IC used on the PCE:GT for the controller is apparently a bit different than the ones in the normal pads, so he got stuck at that point.
The battery life apparently has been extended a ton though, since the GT screen is turned off while the graphic output goes to the RGB monitor.