7tigers, you are correct that a static address would solve the problem but residential Comcast customers can't get fixed addresses.
As stated in the base message, updating my domain's address is trivial using the DNS option in the current firmware it's modifying the hairpin nat rules automaticaly is the problem I am trying to solve.
I guess I could script it somehow and use [ sed 's|x.x.x.1|x.x.x.2|g' ] on my [ config.boot ] and reload but I was hoping for an easier way.