Chevy Chase was selling loans in 2005 that re-am’d only ONCE a year. The teaser rate was 1% over CODI. If you wanted the option of a re-am’ing more often (like every month) you had to pick the teaser rate of 2% over CODI. It was in the fine print underneath the fine print. And yes, it was insanity.

The lender is obligated by law to disclose every aspect of the loan to the borrower – including the re-am period and exact amount of each payment that is credited to interest and principal over the life of the loan. In fact, the escrow can’t close until borrower acknowledges receipt of the Truth in lending disclosure.

OP’s questions are straight-forward enough for a reliable answer from the lender. (I hope.)