I've had a dream of making what I have kind of dubbed the play-recorder. I envision it as a device which allows you to first record the signals that go to your existing ECU. Once recorded you could the play it back to the STM brain board. This would allow you to tune and adjust things until you got your tune to match the known good signals. As well it would allow you to record, then send files off to people who know how to tune, then they could provide you with a configuration that should work. Any how that's been one of my dreams. Has not come to fruition for a couple reasons. One is resources, as we have limited resources and other things are priority. Another is that it seem many people also make very significant changes to the engine, so once they have made the mechanical modes they really don't know what the tune is. So it would have limited use.
Oh another pipe dream of mine. Make an ECU that can control the engine, as well as generate signals to an existing ECU. AKA existing ECU controls transmission, gauges, etc.
I know @russian has connected input signals to both OEM ECU and rusEFI, then moved one cyl to rusEFI control. This allowed him to tune while the OEM was running the engine. Once he got that once cyl tuned, the then connected one cyl at a time until all cy's were running off rusEFI. We have a break out board for that kind of thing found here.
http://rusefi.com/forum/viewtopic.php?f=4&t=454
Lots of cool ideas, but time and resources are a problem.