Unless the gantry can be defined as pintles or rudderstocks, I can not see how they can not be included in hull length measurement? That is my speculation. Only the TC can answer with authority

Personally, I think it would detract from the visual appearance of otherwise fair hull lines. Sorry smile
If it was found to be within the rules, I would have no problem racing with such boats in the fleet. If you actually build it and test it, I will applaud the effort.

Sadly, I fear you will not get your wish when it comes to what you call politics and which I define as something worse. Unfortunately the F16 class have some human resources issues. I am sorry.