<< In BIAB do I have to mute the fiddle for the bars that there are vocals, or is there some sort of setting.
for example, background chording, background melody, solo? >>

No, you don't have to mute. A very common thing is to have the fiddle 'chop' a rhythm when not doing fills, melody or solo.

Example: RT594


BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.