This morning I measured the OLTF of IMC ASC DOF5 loops (attached, OLTF on the right, gain settings on the left). As you can see I'm not using PIT as the current non-aggressive filter is not doing anything useful.
I did on/off test using IM4 trans sum as the sensor (attached middle). As you can see 300Hz intensity noise is suppressed by a factor of 5 at the expense of small gain peaking at around 200-250Hz, 350-400Hz and 620Hz.
Note that the 620Hz peak will be stable against 10dB change in the gain (i.e. even if the peak will come above unity gain), but will quickly become unstable beyond that point.
DOF5 Y loop is left ON.