I am looking for recommendations for providers who really enjoy forced-bi play on the east coast

I don't know if you have experience with this activity but since the passage of FOSTA/SESTA some Dommes no longer advertise or offer it.

When you talk about involving other people in adult entertainment, such as "offering" or "forcing" with a paying client, it could be construed as "trafficking", even if no such thing is taking place. This poses legal risks to all parties involved.

So, while there may be some Dommes who do this, they may not have it on their sites or discuss it with people they don't know.

Even then, they may not allow first-time clients to request it because it has a notoriously HIGH flake rate.

If she does discuss it, expect to vetted and pay a sizeable deposit.

The east has a long and varied coast -- which area are you looking?

I am based in New York, but willing to travel basically anywhere drivable.

There is a good amount of legit desire for this kind of experience. As others have commented, this is not the kind of thing one can find via reading as for other online media. Ask your local favorite (who you have seen at least once or twice) if it something they offer.

In summary: it exists and is awesome!

Look into Vala Syn. She is in NYC. I did a cuckold session with her and did not do f bi, but it was a thing she could offer. Also look into Taking Cuckold Sessions or We Cuck You on X. They heavily offer it. I would also look at Goddess Talia