Try asking, no harm. I'm sure he won't reject you after causing all the problems you encountered.
my reno around same value as yours but like what i said, we changed a lot of stuffs along the way, so the quotations should change alot but he hasn't started calculating for us yet. Some of the stuffs, he did tell us if within his budget, he will absorb for us when we kept asking him to give us quotations. So my FH said, probably this is his reply to us that it's FOC since we really feel that he is good to bargain with. So far, everything is smooth and perfect for us. He progressively did contact my FH to update him what will be done each week and also inform us what we need to start looking around, so that he can have the dimension correctly.
Oh, we changed almost everything in the house. So far abt 1 month alr still at hacking, but not his fault cos we are the one to add in new things to hack along the way, so he needs to reapply the permit. But amazing, he can still keep within our schedule, which is why we really cannot figure out why your reno with him got so many problems. Hope it's not because of us that tied him up, hence he neglected your side. if that is the case, so sorry abt it.