Kouye is correct. The reason why I ask for 20% over the value of the loan is to serve as wiggle room should the exchange rate between the collateral and BTC take a dive. And that's also why I try to keep the loan term to 7 days.
Oh, right understood, I might've not read the thread throughout. I would use this method, but defaulting on a loan is not cool.
EDIT: Read some more of the thread and apparently this has been asked already. Good luck!