I towed my Rib for THOUSANDS of miles with the outboard on. You just have to:
1. Have a dinghy that will do that without swamping.
2. Pay attention to the weather and the seas.
Statements like "never tow a dinghy" or "never tow a dinghy with an engine on it" just don't hold water. You just need to be smart about stuff and know your own boat and dinghy.
No longer posting. Reach me by PM!