I've found that the type of wiring coming from the breaker panel to the dedicated circuit makes a big difference. When I upgraded my wiring to spiral wound multi strand wiring I found my noise harvesters will no longer flash on my dedicated 20 amp circuits. I've moved all 5 of the harvesters to other circuits where they blink anywhere from furiously to casually.
FWIW I picked up one these a while back and it's a great help in tracking down noise and eliminating it. My dedicated lines are around 80-100 mv of noise vs. 500-600 mv on my normal lines.
https://smartmetercovers.com/product...841dfb716d24f9