Quite a bit of research here, in which I see you have played a significant part for several years. Given the reference in Baird, it is interesting that there is nothing to be found in the recently updated lists of the National Huguenot Society.
http://www.huguenot.netnation.com/general

While this is not a final answer to the question of Huguenot origin, it does show that a satisfactory proof has not been accepted by the NHS. Attempts to connect MARKOE / MARCAU with earlier Huguenot inquiries has also turned up negative. That’s the bad news.

On the positive side, a Google search for terms Huguenot and Sint Eustatius brings up a lot more information than I’ve had time to work through. There were Huguenots here with the Dutch, so the question is a matter of evidence as to who is French and who is Dutch (and who might be French by heritage, but born in the Netherlands). Further investigation may require the existence of some sort of earlier documentation as yet undiscovered in my limited review.

Regards,
KA