this would have been useful to me a few weeks ago when i was trying to run 30 vst instruments hooked to separate midi files simultaneously. i ended up pulling the latency down to something ridiculous, and because there weren't any waves running it was a fine workaround, but had i just done this i wouldn't have had to go through the process of mixing out all the midi tracks separately and then cutting out all the silent parts......
all these years, and i had no idea. i will make generous use of this in the future.