At a glance this sounds similar to a mod originally suggested on FuzzCentral if I am reading you correctly since the most common complaint with Compressors is the “apparent” loss of High End or Low End due to the nature of the circuit. It depends a lot on HOW much compression is being used, as far as when tonality differences start to occur. Whatever frequency is prominent, that’s going to get knocked down. That has a similar effect to lowering that frequency with an EQ. That said many people also use a Pre or Post EQ along with their Compressor. A Stage 3 Booster will also give a slight “V Curve” boost in the Highs and Lows to compensate in series after the Compressor. A very nice Combo Build idea.
Our MoRC already incorporates the mod as described on Fuzz Central however we did not see a need to put it on a switch. Most find our stock build to be one of the most natural sounding compressors you can build in the 2 knob variety.
The 0.001 cap per Fuzz Central lets the high frequencies pass thru and that 10k resistor attenuates all frequencies so what you get is a passive hi shelf. We incorporated this mod with our MoRC about 9 years ago so it is already there. We chose to go with a 2.2nF aka .0022uF.
A popular way many compressors deal with any additional “apparent” tonal loss is to add a blend control. We did not find this to be necessary but we do carry a Buff n Blend add-on board.