I also use the rubber duck whilst on the move. I carry two RH770 (one SMA and one BNC) in case one breaks.
I do wonder about the likelihood of damaged SMA connectors on the handheld from use of the RH770. The Yaesu VX6 feels very rugged except for the delicate looking connector. However, the SMA connector is firmly bolted to the metal case via a dress washer…so is damage really likely?
I had suspected that wear of the threads on the connector is more likely over time than tearing off the connector.