Good question, as I just put one of those on a Saito 100 throttle, and I am subscribing to this thread for answers. I was worried about the nut coming loose, and I don't use Loctite around plastic (the plastic throttle arm, as Loctice tends to makes plastic crack, plus any Loctite on the shaft would keep the connector from spinning, as it should be allowed to do), so I bought some tiny 0-80 nylon insert locknuts at Microfasteners to help keep the single nut from backing out. Before installing the locknut, I carefully tightened the main screw on the connector so that it was solid to the arm, but could still rotate with little effort. That process required some trial & error to adjust properly. A second regular 0-80 nut could be used as well, if is simply tightened securely against the first nut, being used as a "jam nut".
I am still building the plane that will use this, so it will be quite a while until I can test it. I do have confidence in it, though.