Is there any reason, other than maybe the ssl certificate error that it would cause, that https isn't redirected to the portal by default? I just noticed that this isn't default behavior. It's a feature that I thought would be somewhat handy and I think only would take a simple ipfw change.
I wrote a quick and dirty patch to do this. It could probably use a checkbox to enable or disable in the captiveportal php page. I'll work on that when I get time.
It's here: http://buraglio.com/nick/projects/dev/pfsense/captiveportal.inc.diff
and I've also attached it.
It has very little testing, but it did work for me.
I'll work on a checkbox for the gui when I get some more time if you think it'd be useful.
BTW, I had ~100 heavy wireless users on my portal yesterday and the load was between 0 and 1% Not too bad at all.
Thats great to hear!!