One Democrat analytics firm posts in-person voter totals on Twitter. Their analyst did this for the 2020 General and again for the 2022 Primaries. He posts charts showing exactly how many voted in-person, by party, ballot requested over the previous 60 minutes. For instance, shortly after 9AM he posts how many voted between 6-9AM. Shortly after 10AM he posts totals from 6A-10AM, and so on. There’s a new chart at the top of every hour, until the polls close.
They have access to this data when the election officially starts, not just election day.