How to tell if you should use the rate choice (previous/current) position 7 in the HEADER parameter in MailStream Plus 8.3.0

Is the rate choice (previous/current) in position 7of the HEADER paramater working on MailStream Plus 8.3.0?

Because some of the new presort logic for May 31st never existed before, it is not recommended to use position 7 in the HEADER parm when running MSP 8.3.0 software for mailings dropping at the USPS prior to May 31st.  

UPDATED:  August 11, 2017