We take security very seriously and so do your current customers. Generally I would say that many companies are concerned about having data in the cloud when we initiate talks. However, they also understand that cloud is the future and the cloud provides a lot of possibilities for optimizations.
When we meet concerns we often try to keep it practical. Not just the cloud is good or bad. We usually ask about specific concerns so customers understand that our solution is most often more secure than having data on private servers. So I would recommend that you ask specifically what concerns they have. E.g. Who has access to data? What happens if the data center burns downs? Is the data encrypted? To get you started I have included some points below.
We have passed security audit at EnerginetDK. This is the Danish government company that owns and maintains all power line transmission infrastructure above 60k volt in Denmark. They use Scopito to document all their drone inspections along with helicopter and ground inspections.