The Reserve Deficit Penalty is 1/10th of the Reserve Deficit. So, if there the contract has issued 1,000,000 Unum, but the USD value is only $900,000, then there is a 10% deficit, and a 1% penalty would apply to anyone who wanted to sell unum for any crypto in the reserve.
ok, so your penalty can be huge if in an event half of your capitalization go out in your crypto.
The main reason to peg a crypto again fiat, is to get price stability through exchange stability (avoid something like getting a crypto loosing 91% of its value). You fixing arent the problem.
If the reserve fell to half the value of the number of issued Unum, the penalty would be 5% - not sure if that's huge, but hopefully enough to discourage others from increasing the deficit.