I couldn't stand it, so I moved some wires and tested the mid cut inductor as the high boost inductor with the caps I had.
You are definitely this week's genius. Of course my faceplates arrived yesterday.
Here's some charts. First is the mid cut moved to the high boost position
, second shows same plus standard high boost inductor (white plots), plus added 7K and 10K using 477mH on that standard inductor.
The curves with the alternate inductor land close to the middle of the EQP-1 bandwidth range, which seems much more useful to me. I smell a hybrid coming. Some experiments with altering the shunt values in the filter section, the 1K and the 5.1K.
changing 1K shunt to 363 ohms increases overall loss another -6dB, 3.75 dB sharper boost at 300, 0.25 dB sharper at 4K.
changing 1K shunt to 13 ohms increases overall loss another -32dB, 11 dB sharper boost at 300, 0.5 dB sharper at 4K.
changing 5.1K shunt to 2025 ohms increases overall loss another -6dB, no sharper boost at 300, 4.5 dB sharper at 4K.
changing 5.1K shunt to 69 ohms increases overall loss another -33.5dB, no sharper boost at 300, 12.75 dB sharper at 4K.
for 1K cut, almost identical comparison between 1K and 5.1K changes; 3.25 dB deeper and slightly wider shape at max change.
Existing max deviation selections appear best compromise for action versus noise. These plots are leveled for identical flat response, you should be able to figure out which curve is which. For each freq, standard/1st opt/2nd opt. Blue plots are the individual stock 300 and 4K for comparison.