Resin Countertops finished with polyurethane

Hello all! I live in a small town so trying to find someone who can answer this question has been hard to come by. I have a guy currently doing my countertops and my island countertop. After two attempts the countertop is done but the island needs to be sanded back down to the resin yet again and a fresh round of "professional grade water based polyurethane" added.

My question is, as I've dealt with different polyurethanes and also polyacrylics, can't you just use a high grit sand paper and lightly sand the first coat of this "PGWBP" and then apply a second coat?

The guy that has been doing it has been either missing spots or having too much drip on the sides or, in this last case, taping off a section of the island and putting on the PGWBP and then leaving the marks where the tape had been placed.

He insists that he can't do a second coat but everything I'm seemingly reading states that he can. Any help would be appreciated. If I'm missing info, please let me know.

Thank you in advance!

Michael