stGIT: commit vs export vs mail

So I am using stgit .8 right now, and I'm having a hard time figuring out what the correct workflow should be for using stg and then committing a change

Here is what I've been doing:
stg new test
  enter my short description on first line
  enter my long description on next lines.
vi file
stg refresh
stg mail <blah blah blah>
or
stg commit

Problem that I'm having right now is that the templates do the right thing for mail, but, the commit only puts in the "enter my..." text.

Is there a template based way to automatically append the author in the 
Signed-off-by: line when i do stg commit?

I realize that I could put Signed-off-by in the log by hand (or even in .git/patchdescr.tmpl which i just found) but it would be cool if the commit just had something like patchmail.tmpl (maybe call it commitdescr.tmpl or something?)

thanks for any opinions or instruction.

Jesse