The HPML repayment ability requirements are set to expire at 11:59pm on January 9, 2014 which means they won’t conflict with the ATR requirements when they become effective on January 10, 2014.
Take a look at the CFPB’s Small Entity Compliance Guide beginning on p. 21 for the general ATR DTI requirements: https://files.consumerfinance.gov/f/201310_cfpb_atr-qm-small-entity_compliance-guide.pdf
I agree with that the general and small creditor QM requires the maximum rate during the first 5 year.
from p. 35 of the SECG: regarding balloon QM…You must determine that the consumer will be able to make the scheduled periodic payments (including mortgage-related obligations) other than the balloon payment. Unlike the calculation of balloon loan monthly payments for determining ATR (See “Calculating payments under the ATR standard for the loan you are underwriting: § 1026.43(c)(5)” on page 21), the Balloon-Payment QM calculation excludes the balloon payment even if the loan is a higher-priced loan,
You can find this in 1026.43(e)(6) and(f).