They also must quit using the 16~23MHz tuning coil carp and actually use 27MHz tuned peaking coils, then any "Super-Feed-Forward" design can utilize the ambient noise sensing - apply it as a function of AGC, not just the NB strip, but Adjunct to, the AGC developed for the RF strip.
Midlands ESP tried to do something like this back in the day using the signal output - as a feed forward means to adjust AGC nearly instantaneously - it worked but didn't develop audio headroom very well.
The unit was a "compressor" that used a comparator - taking in detected audio - compared to the received processed audio, the comparing gave you a difference signal. The difference signal was split - one to AGC the other to the comparator. That output is what the ESP module then summed into the audio line past the ANL/AGC side of the regular receiver - that concept of signal tapping and the processing would work as long as the "window" the comparator used, was big enough to offset the noisy background - it failed when the signal faded - it muddy'd the sound you heard because of the noises embedded in the Amplitude (as an AM receiver) was a problem for the Audio Envelope and carrier it tried to pull out. AGC and the difference it worked the comparator with - Couldn't work it's magic.
You needed a - strong carrier - to get, good signal processing, but once the noise creeped into the carrier you're listening to the station by, the ESP processor of the signal you wanted to hear, the comparator kicked out, the words muffled, muddied together and you lost much of the conversation. The comparator and it's "Threshold" in which to work in, really required a strong non-swinging carrier 2 to as much as 6 S-units above the noise level or the impulse noise.
So when you were in the open traveling - not too bad, got into town and waiting at a light with those polling sensors in the road - your receive washed out. Little noise, yes, but no audio to listen to either.
Similar to the Sound Tracker, but ESP also sent AGC a signal to lower gain, so you "captured" the carrier by signal strength - the ESP brought the detected audio and the pure receive signal thru itself. So the impulse noises and ANL filtering you'd expect - didn't occur, you got the ESP-ized processing instead and it's own tonal drawbacks. - acted like you ran RF-gain down - and the signals came in just fine - but got "chopped" or muffled when they'd fade or arrive to that level the comparator didn't "hold up" and got buried in the noise it's quenching out. It worked the AGC and couldn't be combined together with ANL / Detector AGC stuff the radio had.
So in weak or poor conditions you needed to run the radio like anyone would in the environment - RF gain down, ANL at the ready - to even hear. When you got someone you can run with and talk to, the ESP can get engaged and you're off to the races. The nicer thing was the type of Reponses - any audio with strong carrier close to you can be heard like normal audio and pretty good fidelity even with reverb or echo - not like the ST units where they BOOM-OOm-oom-ed in with fades' as the ST compandor sorted out the threshold - ESP didn't talk - just the receive side - so any help with the output audio was on you.
