Hi! Sorry for the delay.
I dusted off the old mac-mini over the weekend and created a song very similar to your. I played it with pattern length 256 and then again with 16. In both cases the speed appeared to be the same. I would have liked to include a video, but I also didn't manage to record desktop audio with QuickTime (I think we need a 3rd party app for that). How big of a difference should I have noticed?
Any other info you could tell me that could he me reproduce the issue?
-Mat