[massivekerry]

The problem with this idea, in practice, is that a lot of tempo-sync plugins (VIs and signal processing) currently suffer from major CPU spikes when they have to recalculate their playback or processing when you change tempos. This becomes far worse if you program a tempo "ramp" or jump around a lot in a short time period. It's not just Pro Tools. I have colleagues who have issues with it on Logic and Cubase as well. For reference, a lot of these are media-scoring composers, who either need to vary tempo to make video-specific hits (or conforming to a changed video) naturally. A lot of the NI-branded Kontakt instruments will freak out with a big tempo change (or many close together). Multiply that by however many tracks the operator is working with... it just becomes a math and processing problem. I don't know if Avid can add that feature on its own, especially with all of the different processors, platforms, plugins and configurations it has to support. For drums, I suggest just randomizing or swinging MIDI patterns if you want a more "natural" feel. Maybe change tempo in different "song" sections, or do a specific ramp for effect, but you have to be aware of the potential performance trade-offs.