Currently the ability to send messages to students who have not completed the survey is controlled by the core bulkmessaging capability.
At the OU we have this switched off across the board because of the large number of users in our system. Bulk messaging affects a number of different areas of Moodle so if we wanted to switch on non-respondents, we'd have to switch on other things as well. This is not ideal.
I propose to add an extra capability to questionnaire, specifically to control messaging on the non-respondents screen. This would replace the current bulk messaging capability, but would have the same defaults for legacy roles, so existing users should not be affected.
This new capability would allow us to switch messaging on in questionnaire without affecting the rest of the system.