It would be so great if BIAB could grant this wish in a future version. Correct me if I am wrong but Matt and Mac's workaround would be OK but surely the RealDrums then would not be usable for such a song. Basically, for example, you would be creating 2 bars of 4/4 time and then doubling the tempo and then the two bars would offer twice the chord space as a typical one bar (original tempo)and take up the same duration. However most drum parts would not appropriate at this speed and would end up have too many snare hits and crazy hi-hats. It is also likely bass lines other instruments would sound wrong too.

I guess it must be a very tricky matter for the folks at PG Music to resolve or they would have done it by now but it would certainly be the top of my wishlist.