May I ask at what stage during the project would you start using RealBand instead of BIAB?

Let me explain further in my case:

So, I have a melody in Midi form. Importing the Midi into Band in a Box, I would begin to play with the chords and styles. Normally when I am happy with the result, I would just export the audio as a Wav. And that is it.

So will I begin using RealBand after the song is already edited fully by BIAB?