We have talked about this in the past. My conclusion has been that due to BIAB's history and complexity I would not be surpirzed if certain programing features and options look to the Key Signature to make their decision on what will be played. In that case you would need to write your chords in the stated key. Beyond that I have never seen a definitive answer from PGM. I did once try to write a complex key change section. Best I remember it was a bust and I broke the song into 2 different files. But may just have been my workaround. Best to let you ear tell you whats right.

BIAB – 2025, Reaper (current), i7-12700F Processor, 32GB DDR4-3200MHz RAM, Motu Audio Express 6x6 - My SoundCloud (Tip: No need to create a SC account to hear music - just hit ESC ).