I know this is an old thread but thought I'd jump in because I'm dealing with the same thing right now. My duo partner (singer) has retired for health reasons and I want to keep playing as long as I can but don't sing a note, which leaves me doing instrumental sets at the local assisted living facilities. I'm using BIAB 2021 for backing tracks and do everything from 'surf' to country to Great American Songbook tunes. Ideally, converting to Mp3 would be a great idea and I've been doing that using Windows Media Player for playback on most tunes...but...my problem arises when I want to do extended solos over a set of chord changes - say something simple like a 12 bar blues. I set up the BIAB track to do something like 8 choruses, then output it as an Mp3 and use it as a backing track on the gig. Now, I'm locked in to 8 choruses and (in my advanced age) I forget which one I'm on and where/when the track will end. I'll just be wailing away on a great tune and ...boom, it stops. That's where using the actual program comes in handy because you can see how many choruses you have left, plus, you can see the lead sheet or chord chart if it's a tune you aren't that familiar with. Makes it easier to cover tunes you might have a request for and you have it in your BIAB Songs file - just bring it up - set it to an easy key and sight read it on the spot; I usually won't do this with something I've never heard but if I've heard the tune, I can usually pull it off well enough that the customer is happy.
I'm open for suggestions to improve my methods, of course. I'm running the stereo headphone out of my HP laptop into 2 channels of my Yamaha MG10XU mixer, then into one (sometimes 2) Mackie Thump 12 powered cabinet. I'll either run my guitar through one channel of the PA with outboard effects up front or run the guitar through my Evans RE200 amp with effects in the loop. I can run a line out from the amp if needed.