Hmm, if I am reading the GitHub history correctly, I think that the permission check for this feature has been the same for the past 3 years or so: https://github.com/mdjnelson/moodle-mod_customcert/blame/MOODLE_38_STABLE/my_certificates.php#L51

I apologize if this is a silly question, but maybe it will help: is there any reason that accessing the certificates directly in the course is not a useful workflow for your teachers? Obviously, I see the usefulness of being able to see all the certificates for one particular student, but based on parts of your description, I just wanted to confirm what kind of workflow you are trying to achieve.

I do not think that anything at the course context would affect access to the "My certificates" page for Teachers. I say that because of the code, and also because it makes a kind of intuitive sense, since students could be in other courses with other teachers, so not all teachers should have access to information (like certificates) from other courses. Again, sorry if you've already thought of that.

In the past, did you have people assigned to the Manager role at the system level? Can you describe your old process a little more, or alternatively, describe in general what you need teachers to be able to do? At the least, I hope I can help bounce some ideas around.