That's what the PPA insurance is: General Business Liability Insurance. You can also add "Hull" insurance, that is for the gear, like cameras, lenses, drones, flight controllers, etc. Hull covers damages and loss to the gear.
Skywatch is the Flight Liability Insurance. This is the coverage for the flight operations and damages/risk during actual flight operations. I use this for each mission, passing the cost directly to the client. I do this simply because I add my client to each policy as an "Additional Insured". I haven't seen an easy way to do this under a monthly or annual policy, only under the hourly policy purchased for each mission. I don't know about other insurance Skywatch may/may not offer, like General Business and/or Hull.