Good idea (if you would be able to turn it on and off)!
This would be especially helpful to those of us who fly single-engine over WATER and do not have room for bulky life-preserver equipment, or who do not want to wear an LPU all day.
I routinely avoid flying over water for extended periods of time/distance because of this - I do not ever want to DITCH.
I do fly into Tangier Island Airport multiple times a year (small island destination in the middle of the Cheasapeake Bay, Virginia for mission work and to enjoy crab cakes. This function would allow me to know which way to turn in the event of engine loss over the wide part of the Bay.