If you want the same song to sound the same every time you play it, I'd go with the .wav file generation and play the .wav in Media Player or some other program. You don't need BIAB or RB if you are happy with the song. If you want to change it, then go to BIAB or RB. If you really want to stay in BIAB then freeze the song and play it from there, it is essentially the same as the .wav route. Sometimes we try to make things too complicated and/or use the wrong solution for what we are trying to do. This might be one of those times.
Good luck.