I don't have much noise problems. I have humbuckers and a shielded guitar. The only problems are when using ST9+Pro in a Fat Rat stack, or ST9+Pro in the red channel of my 5150 III. In other cases, when using a clean channel, or separately overdrive and distortion, there is no noise as such.
I connect this pedal and after turning on there is a significant noise, even without the included drive pedals. In a bunch of ST9 + pro and a fat rat, the feeling that the noise becomes many times greater. You try to get rid of the noise and turn the knob, but the value at which the noise ceases to be heard, or at least at an acceptable level, already kills all the dynamics, tone, sustain, and it simply becomes unplayable. Yes, I use the 4 cable method with the FX loop of my amp.
As for the boost, it sounds very good, but how to use it is a question - when it is turned on, the noise level increases exponentially.
The only use of this pedal is in a clean channel with forming distortion in front of the amp.
Perhaps the best use of this pedal is to nail it into the wall, still beautiful.
I don't know whether to laugh or cry, but the built-in noise gate on my second amp (EVH 5150 ICONIC) works better....