I do have some shock cord so I may try adding that to the painter.I added a length of shock cord alongside a few feet of my dinghy painter; maybe about 6' of shock cord parallel to 4' of painter. Whipped to the painter every 6" or so into roughly equal-sized loops (a nice evening project while watching a movie with the kids). When towing, the shock cord stretches fully and the main painter takes the load, but it reduces the constant 'jerking' a lot. Hopefully that description makes sense. If not, I can dig around in the storage tubs and take a picture. The shock cord might degrade quickly in a sunny climate, but up here in the PNW, it's been fine for a couple seasons.
Use a electric trailer emergency break actuator cable that normally attach to bumper would be tied to dinkafter a friend lost his very expensive hard dingy in the chesapeake, we mused , with some dark and stormies, over a dingy alert system. it would involve rigging a very thin wire between dinghy and mother ship. the wire would be connected to a 12v battery source and an audio alarm . if the dinghy broke loose, the wire would disconnect and an alarm would sound on the mother boat. we never did fulfll this design because it was easier to just go buy a stronger painter.