I agree the Florida program is not perfect. Why are we allowing credits for all-a-carte items that have no bearing on damage reductions unless they are part of system of components that can, if properly designed, reduce damage?
For instance, we allow credits for clips/straps but the roof could be old or worse tile and the deck attachment may be staples. The clips/straps in this case do not provide any reduction in damage because a minimal hurricane can damage the roof covering and decking causing significant water damage and interior loss.
As stated by many above, the Florida Mitigation Credits are what they are and the program is in the hands of the legislature and OIR so we have a duty to comply with the definitions in the form or be subjected to penalties, fines, suspension, or imprisonment per s. 627.711(4).
I disagree with the premise that porches pose less of threat, they are by definition “partially enclosed” structures and subject to considerably more uplift during wind events. They need to be tied down to the beams and the beams and columns should also be tied down to transmit loads to the foundation. Otherwise they become extremely large airborne missiles capable of significant damage to the host or surrounding structures.
If these form a part of the host roof structure (structurally attached) or are enclosed they are counted in terms of geometry, roof covering, decking, and roof to wall. If they are not enclosed and attached only to the wall or fascia of the host structure they are ignored. Hope this helps.