If your DAW allows it you could do what I do. I render the BIAB real track to a WAVE and drag it to an empty track in my DAW. For back ground instruments I will usually render three re-generated tracks and drag each to its own track in the DAW. I then highlight the 3 tracks and choose to implode tracks into a take. What you end up with is 3 WAVE files on the same track perfectly aligned but all different. I then split the track at each bar. What this allows is that when you listen back you can select and highlight which split section of the three tracks you want to hear.

It's similar to the multiriff function in Realband but in my opinion I can get much better results. You can get even finer edits by splitting the measure into 1/4ths. Using this method I am only editing 1 track versus several tracks. That means less volume envelopes and if your working with DI guitars and an amp simulator you need only one instance of the effect open conserving resources.

For solo instruments I usually render 8 tracks minimum but have done as many 12. Again they are imploded to a single take on a single track and split. For an example of what's possible. The following song was made with all real track files and custom editing.
https://soundcloud.com/jsting1/canyon-mist

This is just one way of many to custom edit real tracks. All the ways mentioned accomplish the same thing and it really becomes a matter of what works best for your work flow. You can make truly unique original compositions if you spend the time.