Here is another old one.
But notice how many of those old ones that switched from VFD to a CSV have never come back with a complaint. As a matter of fact they haven’t come back to a pump forum since, because they no longer even think about their water system. That is the way it should be. Your water should be so dependable that your neighbors on city water should need to borrow from you more than you from them. Simple is what makes it dependable.