Two points to stir the pot a bit more:
There is currently no restriction on the mast step height. In theory, if you take away the pin rules, you could have a deck stepped rig unless you add in some new rules to define the height of the mast step.
Also, on the carbon debate: Has anyone else noticed that there is nothing in the rules to stop us using carbon tillers? Do we close this loophole, or accept carbon tillers? A suitable carbon tube would cost about £60. Or am I way behind and carbon tillers are in use already?