I have very poor eyesight so love the big lyric window. Problem is everyone advises NOT to use BIAB to perform live. How do I save my backing tracks as kareoke and what is best way to play them live?

Why can't you use BiaB when performing live? I believe that Danny Campo and others do it. You might want to send Danny a private message and discuss it.

i recommended not using BIAB live. mp3s are simpler and its easy to have a back up.

however, i always used to have my lyrics on a music stand printed out large enough to see.

no more obtrusive than a laptop running BIAB

While Band-in-a-Box can be used for live performances, some people find the starting/stopping and Jukebox options not to their tastes, and I have heard of others saying they prefer to not have to worry about the way the cursor moves through the song. You can set up the Jukebox to a specific folder that contains your songs and use that for live performances if you so desire, but depending on your preferences, you may also prefer using your rendered files and loading up a setlist for yourself outside of the program either just in the file explorer using Windows Media Player or through a third party application of some sort.