One thing that does seem clear in the Election Day numbers is that the GOP vote came out early but the vote is becoming less Republican (and more indie) over the course of the day.

e.g. in Broward County (the rare FL county where Democrats are winning the Election Day vote)

From 7am to 1030am, the vote was D38/R34/I28 (D +4)
From 1030 to 1230pm, it was D39/R31/I31 (D +8)
From 1230 to 3pm, it was D37/R26/I37 (D +11)

From 3pm to 4pm, Broward was D41/R26/I33 (D +15). So this gap keeps growing.

I know that it's not uncommon to see these sort of shifts, but these seem like pretty sharp ones. It could be that the voters who showed up at 7am (usually enthusiastic/reliable voters) were atypically Republican because the most enthusiastic Dems voted early or by mail.

Among other things I would be VERY CAREFUL WITH EARLY EXIT POLLS. Even more so than usual. If there are big splits in the partisan composition of the electorate over the course of the day, and we're seeing that in FL, AZ and NV, exits conducted early on could be quite misleading.