JeffK suggess that the changes in this TF may be due to the unlocked HEPI reducing the frequency and Q of these HEPI modes in the ISI.  I can only find HEPI unlocked but with no fluid flowing for HAM3.  In this attached plot, the modes in question (between 10 & 40 hz) have not changed.  Maybe the fluid needs to be flowing, maybe the loops need to be closed as well.  This is why we need to collect lots of data still.