I did some dual towing out of Husbands Bosworth in 1998, testing winglets (one glider with them, the other without) - seemed like a cheap way of getting both gliders to a decent height at the same time and place.
The first couple worked OK, but on the third the glider on the short rope dropped a wing and ground looped in front of me. I managed to avoid it, only just though. So, not without hazard.
I might add the the ground loop was made more likely by the length of H-B's grass. They never seem to keep it short, but it was particularly long that day.
OG