I'm not sure I understand what "fun scale" is. I'm assuming the judging is done at a different distance but could you, if you wished, enter the same model you'd enter in "expert class" in "fun scale?" That certainly would seem to take the "fun" out of it.

I'd assume that what a serious scale modelers might consider "fun scale" would be better than the best some other modelers might every be able to achieve. For example Art's fantabulous EII was entered in "Sport Scale" I believe.

This is just curiousity really as I don't imagine I'll ever compete unless there just happens to be a conveniently located scale event and I just happen to have a scale model in flyable condition at that moment.