Okay, here's the deal in a nutshell.
CONDO's ought to be insured for the full RCV..OR, $250,000/unit.
If not and if they are underinsured by <80% of the full RCV at time of loss, there will be an additional co-insurance penalty that even additional insurance will not cover. This is a HUGE S&S issue...[do the math!]
If they are somewhere between 80 - 100%,then I would require a general borrower-aquired policy for the difference. Again, considering the $250k/unit limit.
I hope this helps you.
Release the mortgage or insure adequately...those are your options.
_________________________
My opinion only. Not legal advice.
Say you'll haunt me - Stone Sour