First of all, I would like to thank the Kobo community for the amazing software and the support that we received here.
We are working on a project to deploy kobo toolbox for a non-profit organization in India. One of the missing features in the current system is reporting. So we decided to use another open source project BIRT reports to build reports specific to the organization.
Using the BIRT software we were able to directly connect to the Postgres DB. We had few challenges while building the report as the data was in JSON encoded format. But after resolving the issues we were able to generate the report as per requirements.
You can check out our sample report here