Hi Ben,
The update interval for timelines is fixed at 30 seconds, and we don’t presently allow adjustment of that. We wanted a sane balance between new Tweet frequency, server load on our side, using user bandwidth on the client-side, and the performance implications of regular processing in your page.
Adding an option would be quite easy if there’s a strong use case for it. What kind of frequency are you looking for, and with what kind of timeline?
Thanks,
Ben