I agree about slowing to pass but I can't believe that using a bell does nothing. It's been the single most effective warning device I've ever used. Far better than a human voice that blends in with all other human voices on the path. It's also a friendly sound that doesn't come off as a command or whatever. It cuts thru all other mechanical/human white noise like nothing else and is distinctive over longer distances. If you aren't getting results I would suggest simply ringing earlier and more often. I have never failed to get clear passage since using it. The one I use is no bigger than a quarter. It gives a pleasant but clear ting-ting sound. People turn and look. They almost always go to the right, often with a smile, and always in time.

The "on your left" notice is a recipe for disaster. If not for laws and modern medicine, half of us would be dead of stupity. A similar thing happened to me as with the OP. Sorry the OP ended up in court - my incident simply forced two Twalkers to collide as one went left and the other went right - into each other. I ended up in the bushes.

MUP's in general: A constant potential flashpoint in my opinion. To be used by cyclists sparingly, especially in good weather when all the Twalkers are out. In most cases, I think streets are better, or at least just as good, at getting you where you need to go. You can go as fast as you need to on streets. Do that on a path and you deserve all the grief you get (not implying that the OP was going hell-bent).