If you create a song in BIAB using RealTracks and allow automatic substitution of the RealTracks based on tempo, it replaces the RealTracks used in the style. If RB then opens a BIAB track the song summary lists the original RealTracks in the style not the ones substituted.

The tracks uses the correct RealTracks (the substitutes) but it confused me and I've only just worked it out!