I need someone to educate me on this a bit, as I'm confused...

A month or so back, we had trouble with Mac Pass-thru.. Instead of looking
into why, our first troubleshooting step was to add an IP pass-thru rule and
it worked.  We were busy at the time, so we didn't think too much more about
it...  Today, we added another Mac pass-thru rule for a different device,
and it also did not work...  We added an IP pass-thru rule and it worked
fine..

I had a bit of time to look into it today, so I decided to dive into the
code to see if I could find something wrong.  

Unfortunately, I don't see how the pass-thru MAC stuff ever worked, based on
what I'm seeing now.  Perhaps I'm overlooking something.  Granted, I'm not
very familiar with ipfw, but from what I see, the
captiveportal_allowedip_configure function creates a database of IP
addresses that are allowed through and adds appropriate rules.  Similarly,
the captiveportal_passthrumac_configure function creates a database, but
doesn't add any rules.  I can't locate any other code that references either
the $config['captiveportal']['passthrumac'] variable or the
captiveportal_mac.db file.  

Am I missing something?  Is this feature working for anyone?  (I'm running
1.21r92)

Thanks,
Paul