<< Thanks, I will go experiment with this info on a test project. I actually think some of those setting are causing BIAB to do things I do not want. If you don't know this software well, there are all sorts of un-commanded actions that will take place. >>
AKA - auto accompaniment...
There's also the method of how the chord chart is setup to react to the Chords and progressions. The way I express it is the chord sheet, bar setting and song settings can be set to address auto accompaniment as semi-auto accompaniment process. Accompaniment can be accessed in BIAB in a similar fashion to pre and post send settings on an aux send of a mixer board. Every BIAB render reacts to commands differently from things that are input into the chord chart than from commands set by Bar settings. Results that are affected include mute, back to normal, transitions, fade in's, fade out's, instrument changing when using the Medley Feature, cross fades and more.

<< In general if I type in a C chord, I want C, not C7 and if I type it in a few measures later I want the same sounds to play. I am having difficulty getting BIAB to stop changing things I don't want changed. >>
AKA - auto accompaniment...
In this situation, not only are the commands listed above that affect each render, BIAB provides an advanced 'freeze' feature that's a very powerful tool that's easily accessible, provides the means to freeze and preserve a track exactly as it's render is at that moment. Allows regenerations without losing favorite phrases you want to preserve, save for pasting in other bars to replace unwanted phrases. Changes the BIAB Mixer track's color making it obvious the track has been edited and this feature works with any sound media type that BIAB recognizes, Recorded audio whether WAV, AIFF, MP3 or RealTrack. MIDI, MST's or any combination of these media types. This feature is included in every version of BIAB, PC and MAC. This feature is accessed from the BIAB Mixer Track sub menu - Track Actions/ Save Track as Artist Performance File (WAV/WMA)

<< I finished a song and froze all tracks. I then told BIAB to generate a four bar intro, which it did. It also changed measure three of the song I had finished even though it was frozen. Evidently frozen does not really mean frozen. I am not sure. >>
In other automated BIAB generated tracks, BIAB automatically adjusts to begin a phrase some tics early and some tics late to create a smooth transition. If you used the BIAB add intro feature, it may be the smooth transition is automatically detected and implemented. A pre send feature I described above.

<< I also decided to add measures at the end. I reset the ending bar and new blank cells open up and the ending bar displayed normally. Problem is none of the new cells will play. >>
This is a post send command that a BIAB regeneration responds to after it has internally read ahead and created the markers to the RealTrack audio file. Since you froze the track, BIAB applies this post send command and ignores generating and adding the 'new' chords on the Chord Chart.

I have no knowledge that any of this is actually how BIAB algorithms are programmed to work but have found various clues and references over time from the manual and post comments and also from the commands and processes available to create UserTracks.

If I treat these commands and functions as if they are true, for me, they've always reacted as if they were true. In other words, they work as expected. Places to note they work are Soloist intros and outro's and instrument transitions between instruments when used on a Medley Track and mute/back to normal transitions.

Artist Performance Tracks and UserTracks are both BIAB user created audio files that can be located on any BIAB Mixer track. Very useful and powerful tool.

Here is a post I made back in February giving more information about Artist Performance Tracks.
The case for Artist Performance Tracks

BIAB Ultra Pak+ 2024:RB 2024, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.