Fee: in my case, they didn’t charge me anything, because I just asked them for the ballpark number. Then I decided to pay off, and they sent me the exact number (who cares if the 100 or 200 dollar fee is charged or not).
Another point I think people need to be aware is that the MR typically increases year after year. I don’t understand the mechanism why this is the case though. Paying-off the MR thus also avoids future increases.
