We are glad that your solution is working as per your expectation.
We would like to understand what sort of production tests you would like to perform on the units. Will the test be conducted with the sensors connected to the main boards using wires or do you want to perform these tests without the sensors connected?
We would recommend you to use the Built in Self test to check if there are any issues with the sensor hardware such as
1. sensors to sensor short
2. sensor to ground/ VDD short
3. Cp within limits test,
4. Cmod within limits test
5. Check if the rawcounts is within expected limits. For a given IDAC value, you could expect the raw count to be within certain limits. If you find your rawcounts to be abnormally high/ low / zero/ saturated, you could take that as a failure
Refer capsense component datasheet for details.