u/kenglaze

My contractor “filled”, sanded, stained, and has applied two coats of oil based polyurethane to my hardwood floor. I notice areas where they failed actually fill some gaps. They are going to proceed tomorrow (Thursday) and said these gaps will be fixed. What is the best or proper way to fix this?

I’m betting the right answer isn’t an extra heavy final coat of polyurethane, right?
Can additional thin layers of polyurethane fill these in?
Should he fill with wood filler and apply stain to the filler and then coat again with poly?

Please help!!!!! if you are a professional and have real experience and input I need your comments quick!!!