Doesn't Rockland County have a large Orthodox Jewish community? I am thinking Trump's stance on Israel be it moving embassy to Jerusalem and deals with a number of Arab countries to recognize Israel would help him there. But looking at precinct data in 2016 he might also already be maxed out in this community.
I think it's mostly because they hate the anti-coronavirus restrictions. Although you are right that they were already a solidly Republican group, so I'm not sure how much room Trump has to grow.
New Square in Rockland might have gotten bribed by Bill 20 years ago so they voted for Hillary but they voted for Trump this year probably.