$130 per month sounds remarkably cheap  for liability insurance on that many drones doing custom work. That is unless they have a very low level of coverage. Perhaps if you have little invested,  you have little to lose. I would think the owner of the drones & equipment would have much more insurance due to the liability chain of responsibility. I would think most drone flyers here have checked with their own farm liability company re. drone insurance. Usually the results are disappointing.

A few yrs back, there was a company I used when flying drones that could buy insurance on a "per occasion" basis. For instance, if you were going to be flying at an event where there were lots of people, you might want some insurance (liability only). Pick up your phone and tell it where you were flying and you were covered instantly, however each locale had different rates. Out in the middle of nowhere, it might be $15 for one hour. Near or in a village, then $40 per hr on your cc.

That company ceased business. No longer available. Disappointing.

Coup, if you could post the name of the insurance company being used by your custom lessee, that would be great. No personal names needed, just a company name reference.