I had 3 water leak claims last 10 years (6 houses). My insurance company would always keep some (10 or 20% I forgot) payment until the completion of project. Contractor can negotiate with insurance company if they find out the repair cost is higher than estimate.
Tile/floor matching is tough sometimes so repair estimate could include changing everything in that area (could be a few times as large as affected area). In one ongoing claim I am in, the mitigation company wanted to break up all granite countertop. I insisted NO so a granite company came to take them off. There were a few small chips but I am ok with that. 50% saving compared with getting new granite countertops, not to mention longer project time.
I had to order some backsplash tiles on internet in order to match current ones. Shipping cost twice as much as tiles themselves. I need to save some money to prepare premium increase.
Allstate is really good in term of claim.