Any updates on this? Is it just the SF2 format that is blocking you?

Well yeah, sorta. The only second solution I can think of is to write my own sampling engine like the one in Abe's Exoddus.

I'm studying how to pitch shift in C++ with SDL for my own little 2D game engine I've been working on. So as soon as I've done that, I won't even need to use a sf2 file, i'll be able to play with the samples directly.