Early Long Island under the Dutch had many people going back and forth in the religions and dual religion marriages where husband and wife had different religions. Baptists going to Quakerism going to Dutch Reformed to Anglican and all back again.
The Quaker ban on interfaith marriages came after this period. Quakers at this time had members and attenders. As an attender, or a friendly, you could attend Quaker meetings and participate in Quaker services and still be a member of another church.
What I do know is that Presbyterians in NYC, NJ, and PA did not get along until after the Revolution.