Simon,
All you said is intuitive, correct and good information but doesn't really explain why PG Music combines some chord labels under one label.
I'm not sure I know enough chord theory to provide a good example but several examples are given in earlier posts to this thread.
My thought is since BiaB started as a midi based program the program should be able to accept and display almost any chord. In cases where the displayed chord does not match RealTrack audio, the RealTrack transcription should be updated to display the recorded chord.
I know I for one use BiaB as a learning tool. Learning how a chord sounds is difficult if not impossible when the chord displayed does not match the audio playback.

Jim Fogle - 2025 BiaB (Build 1128) RB (Build 5) - Ultra+ PAK
DAWs: Cakewalk by BandLab (CbB) - Standalone: Zoom MRS-8
Laptop: i3 Win 10, 8GB ram 500GB HDD
Desktop: i7 Win 11, 12GB ram 256GB SSD, 4 TB HDD
Music at: https://fogle622.wix.com/fogle622-audio-home