Sorry guys, I`m partly (if not mostly) to blame here..
When I first came across the F16 concept it was an idea of a class that allowed similar 16ft boats with spinnakers to compete on a first-in wins principle, all off a non-handicap basis. I spoke to Wouter who was then the class chairman about the Mozzie, he had indicated then (very early days) that the goal of F16 was to be as inclusive as possible, allowing us, H16 with spinnakers and even Dart 18 with spinnakers to compete as non-fully compliant designs. This was at the start-up phase of the class.
My motive to have us included in F16 was to try and promote cross-class competition in South Africa, as the Hobie class was experimenting with spinnakers, there were a few Dart 18`s with spinnakers and a few Mozzies with kites as well. At the time none had adopted the spinnaker as class equipment, so sailing with kite made you a bit of an outcast in your own class. Hence the desire to promote a new open-class spinnaker fleet with no handicap, which I believed might be successful.
Since then the Mozzie class in S. Africa has adopted the kite as class equipment, and sail off an unofficial SCHRS of 1.13 (not verified by a SCHRS official), which I calculated with the help of Robin Smith at ISAF. As a result of this we no longer really "need" to be a part of the F16 class, especially since the H16 and Dart 18 sailors who had kites have since given them up as they are not really suitable boats for spi sailing, and we are no longer allowed to sail at Hobie class organised events, se we seldom get to compete with them anyway.

I`d just like to dispel a few myths :

"SCHRS treats square tops and pin head mainsails as the same, might not do to well under that system."
This is not strictly accurate, there are a number of measurements taken on the mainsail, measured according to the ISAF sail measuring method, that are taken into consideration. The bare minimum that are required are luff length and sail area, but the option of entering all the details will give a more accurate rating. I also believe that they have updated the formulas recently to deal with this issue.

"SCHRS also penalises larger centreboards which is not good for Mosquitoes since we use centreboards with nearly half the area allowed under the class rules."
Also incorrect, the formula penalises long high-aspect ratio daggerboards, whereas the Mozzies are short by comparison, so the SCHRS formula takes aspect ratio, (board area & board depth) into account.

If the Mozzie class in Australia has also adopted the spinnaker as class equipment and sail off their own rating, it might be beneficial to disconnect the ties to F16 (if indeed there are any). Ultimately any class that fits the F16 boxrule can be classified as an F16 - The Mozzie complies in all respects to the boxrule except for minimum weight, which is why we were given grandfathered status, as it was offset sufficiently by us being under-specced in other areas such as max. beam and mast length. Whereas we comply with the boxrule, we are not optimised to it, and as a result cannot possibly be considered to be as fast as fully optimised boats (except in 28knots plus, where a well-sailed Mozzie is faster than an upside-down F16/F18 ;))

Hope this clears a few things up,
Steve