You will wait...
Regardless of system. I tried hard finding a way to make it faster..
Regeneration process, that is what's taking time. I think it is a little bit faster if you "preview" in stylepicker rather than opening style in main window...

In my opinion, mostly, it has to do with individual tracks being loaded from original source instead of loading them into memory (which should not be a resource issue for most modern computers)

So, each time you change a chord or such in main page, BIAB will go to the source file folders on your hard drive to OPEN->generate instead of just generating.

Some weeks ago, P.Gannon talked about speeding things up (generation)
I hope it included BIAB in that plan, not just plugin...