Just so everyone is on the same page,
this is the Coverage Form you are referring to (I believe).
You are absolutely correct. Flood insurance must be purchased for the lesser of the appraised value, loan amount or maximum available. The amount of hazard insurance is not a consideration for the calculation.
I don't like how this is presented on the form either. However, when conducting audits of flood loans, I do like to look at the amount of hazard insurance. On several occasions I have seen the amount of hazard insurance in an amount greater than what the lender assigned for the appraised value for flood insurance.
When questioning the loan officers about this, typically they admit that they were trying to get a low number for flood insurance. The borrower, knowing the value of the property, purchased a higher amount of hazard insurance. I then explain that if the value is $X for hazard insurance, then it must be $X for flood. You can't insure something for more than it is worth.
So, this is a good cross check, but you are right that it should be used as a calculation number to derive the least amount of flood insurance.