From the ProjectReport object it's not possible to know whether a certain module/category was analyzed. We can only check the number of reported issues associated to a category. Basically, if a category has zero issues we don't know whether the category was actually analyzed vs no issues were found.
To update an existing report, the user must manipulate the ProjectReport object since this is not supported.
Solution
Add information to the report so it's possible to know which categories were analyzed
Add built-in support for updating an existing report.
Problem statement