I wish I could compare, but I moved into a (large) new home with a smart meter. I have no measurement that I can compare it to. On top of that, I just replaced all bulbs with LED, and wonder if that has been counterproductive.
I've seen once little screw for bulbs it said on the box that it corrects wave so it's stable. It said that it extends life of bulbs. Not sure if it would help or not as the problem seems to be coming from appliances having chaotic usage wave patterns, but who knows maybe those work both ways, anybody knows?
The most expensive would of course be to put CT's on each circuit in the house.
Least expensive would be to source a meter for the main.