Welcome to the forum. I just wanted to confirm that this is one of the most requested features. You are not missing anything; BIAB is not able to do this.

I sometimes enter chords as notes in the melody or harmony track to simulate the missing chord.

Another trick you can try is in the Edit menu, where you can expand the length of the song to twice. Using a different tempo, you now have the ability to place chords on consecutive quarter notes. What used to go in one measure is now spread over two. You have to try different styles, and it doesn't always work, but sometimes it does.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.