Continuing on the track of modifying the existing camera app, I figured out how to write out the right data so the video will play back at the intended (fast) frame rate.
Another item I had to do was to make sure the auto power-off shutdown doesn't kill the video capture in the middle of capture.
After that was done, we can take time lapse video with the superconference badge camera!
Unfortunately, YouTube applies over-zealous compression to this video footage. The camera is already so low-resolution that the video files are tiny, but YouTube crushed even more detail out of the already minimal amount. I had no luck figuring out how to tell YouTube to stop that.
In the meantime, this clip just gives a (very) rough idea. You'd be much better off downloading the raw AVI files from the "Files" section of this project.