Been using a radio lanyard when fishing solo for 8 years, love it!!! The sender is attached to my PFD which I also wear when fishing along.
These items were negotiated with the Admiral as "MUSTS" when I'm alone out there, which is just about 99.9% of the time, even before this past year.
I always wear a life vest when I'm out alone. Never see any other people wearing one other than children. You fall over when the boat is moving fast , you'll go under and all it takes is one gulp of water and you drown. Drowning happens in a split second, it's not the long drawn out event you see on TV.