@David_W:
RFC 4638 support was merged to pfSense 2.3 earlier today, shortly before 2.3 was redesignated as a beta.
I didn't follow any of the procedures relating to bounties before starting to work on this, and it would probably be rather out of order for me to expect any payment for the work I did to implement this.
Should any of those who pledged wish to pay up, I suggest they donate their pledge to the FreeBSD Foundation.
I've just seen this and have done as you wished :)