It is annoying that not all the messages that go to the screen go somewhere else. As one possible reason for this, I'll just tell you what happened when I tried to alter the scripts to write more stuff to a file: it didn't work.
The problem is that early in the boot process the file system is read-only (or at least some of the file system is). Then the fact that I got errors from illegal writes in turn caused more serious problems. At least that was my interpretation of what happened. I backed out the logging, and things went back to normal.