I noted that some of the given examples don't work when there is a ? (question mark) or : (colon) in strings within the query. Substituting CHAR(63) and CHAR(58) respectively allowed the characters through. For example...

WHERE rc.capability IN ('moodle/course:upd' || 'ate', 'moodle/site:doanything')) AS teachers,

...can become...

 WHERE rc.capability IN (CONCAT('moodle/course',CHAR(58),'upd') || 'ate', CONCAT('moodle/site',CHAR(58),'doanything'))) AS teachers,

It would be good if the report plugin could be updated to work around these characters or if the examples could be updated to include the CHAR() substitutions.