@GatorDad305 I’ll take the contrarian point of view on this and say that it will have only a modest impact on the overall number of applicants. I agree with you that the effect on in state applications will be negligible. But, I believe that it will also be a small impact on out of state applications.
My thought, and experience with a small sample set of 2 kids, is that students were already making the effort to use the other application if they were interested in applying to a school that required it. Especially if they are high achieving students that would be most likely to apply to UF. Neither of my kids decided to not apply to a school because it required them to fill out another application. They applied to the schools that they were interested in, regardless. Also, even if you already have the Common/Core application filled out, there are school specific questions and essays that have to be completed. So, it is not like you just have to click another box and then it is off to UF. I feel that there is still a sufficient effort barrier that will discourage those students that are not all that interested in applying to UF, but would do so if it required virtually no effort and no $.