"Leading" is incorrect, but modeling has assumed D's need a 70-30% advantage in mail voting. This is because of polling regarding COVID where R's are less worried about early IPEV and more likely voting on election day. The current numbers are nowhere near that, so I wouldn't be surprised if Florida is red.
Uh... whose modelling? We've never had a pandemic election, I think it's fair to say no one has any idea which demographics are more/less affected by an early voting drive. All we can say is that a whole lot of people are voting early.
>Most people believe more Democrats are voting via mail
It's not necessary to "believe" anything when it comes to Florida. We have the actual hard number of ballots requested and returned, broken down by party registration. More Democrats are voting via mail. They're also voting in-person in equal numbers to Republicans, at least so far.