Interest paid on CDPs can be used to help the peg. 20-30% is a sizable portion of the debt and can provide incentives for the CDP owner to make a promise.
The promise of the CDP owner would be that they have to pay off their debt at a certain price if IUSD starts to depeg.
Bob is a CDP owner and has 100 IUSD in debt. Bob is willing to pay off his debt and burn his IUSD for a price. The interest that Bob pays will be 20-30 iusd per year. Once Bob gets up to 10 or 15 IUSD in interest paid he can qualify to make this deal.
Bob wants some of that interest he paid back and doesnt mind getting out of his CDP at a certain % gain. Hes willing to pay his debt back at some point anyway, he doesnt plan on selling IUSD for good.
The solution is for Bob to accept 10 IUSD back from the interest that he has paid. In order for Bob to receive the 10 IUSD he would need to sign a contract that he must burn his 100 IUSD if the peg hit .90.
Bob is basically selling a put option in his IUSD debt. hes getting paid to have a limit order to burn 100 IUSD at .90 in exchange for the 10 IUSD.
If IUSD does not hit .90 then Bob hangs on to his 100 IUSD in debt and the 10 IUSD he received from the sum of interest he was paying.
This means there will be a massive burn if the IUSD starts to depeg past .90, or whatever level we set it to be. Causing a ton of burn would help the peg to get back up.
Bob is getting a nice return and is basically willing to hold iusd for longer so he can get up to the 10-15 iusd in interest paid returned to him.
Bob is also helping to keep a hard peg and assure he will be buying his IUSD back at some point.
This also provides a huge incentive for all CDP owners to help to keep the peg healthy, because a healthy peg, above .90 in this example would mean everyone keeps their 100 iusd debt and also get to keep that extra 10 iusd that they are getting back in interest, and can continue to get this incentive in the future when they have paid enough interest again.
the interest would be returned by a certain time. perhaps they can accumulate a return and receive it once their iusd gets burned. or get the 10 iusd upfront when they sign the initial contract to promise to burn at the specific depeg strike price, ie .90.