UPDATE.
An hour later there was a thick coating of yeast and another reading by refractometer showed the first to be suspect to say the least. Obviously another should have been taken at the time and I might then have considered cropping the yeast. Now it will be left peak, then crop the yeast later today leaving a thin covering to protect the beer. That will be 3 days from pitching and a gravity reading will determine when the beer will be left to cool and clarify, to be likely racked on Monday.
An hour later there was a thick coating of yeast and another reading by refractometer showed the first to be suspect to say the least. Obviously another should have been taken at the time and I might then have considered cropping the yeast. Now it will be left peak, then crop the yeast later today leaving a thin covering to protect the beer. That will be 3 days from pitching and a gravity reading will determine when the beer will be left to cool and clarify, to be likely racked on Monday.