The Steps to create more than 8 tracks in the BIAB Mixer:

BIAB emulates the multi track recording process really well when used to record on the single Audio Track and also if used to bounce a Style of 5-6 tracks down to a stereo audio file. BIAB only has one Audio Track (Channel) but that one channel for Audio recording can be used multiple times.
To bounce a Style just render and export the song to a WAV - Import the WAV back into the Audio Track, convert the audio to a Performance Track and move the Performance Track to any of the channels. You have a stereo mix of the song style so all of the Style tracks are now available to be replaced with additional instruments or even different Styles.

This process can be repeated multiple times because Performance Tracks can also be rendered to a stereo WAV mix, imported and replace the mix and this mix can replace existing single Performance Tracks that have been bounced down to a mix.

Another method to use the Audio Track for multiple takes is almost hidden. Select the Record Audio Button from the Transport Toolbar, in the window that opens, there's a check box beside the wording, Overdub underlying audio. Checking that box allows recording another take of audio without overwriting the existing recorded audio and BIAB applies a preset mix of the multiple takes. This process can be applied multiple times so perhaps if you're recording a vocal, using this technique and process, you can double your vocal, record harmonies, backing vocals or even play an instrument to add to the track. The BIAB preset mix does a good job with the mix and it's done digitally so there's no noticeable degradation of the sound.

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This demonstrates how to have dozens of instruments on dozens of tracks and multiple vocals added to the instrumental backing tracks all from the 8 track BIAB Mixer with a single audio channel.

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.