*I know the answer is nobody needs to know, and many people do it, but at some point the lenders may come after those 3% notes when the rates are much, much higher.

I saw this last time the rates shot up, as business slowed down, the lenders then checked on some of those low interest notes to make sure the owners were still occupying the properties. When they weren't, they'd call the note due or offer to refinance into a much higher non-owner occupied loan.