I don't have an answer for you. But, a few years ago there was a "per occasion" drone flight insurance I used. It had a phone app and if you were going flying & wanted to insure the flight, you could buy 1-2-3 hrs insurance on the spot. Charged to your cc. Charges were dependant on the when/where you flew. If you flew out in the middle of nowhere it was cheap per occasion. Fly in the middle of town & rates raised. But, they always showed you the rate before you hit the INSURE ME button.

I guess they didn't make enough money since they quit offering the service. Too bad, it worked fine.