UI for creating multiple individual cohort sync instances to multiple courses

I'm looking for the ability to take a System level Cohort and assign it to a Role at the Category level that would give them access to all courses within a Category. Currently whether the Cohort is created at the System or Category level they can only be assigned to a role at the course level.
At our institution over the course of a year we could have up to 4500 courses. Adding a cohort to each course is not possible. I know in the past there was Category enrolments and that has been deprecated in place of cohorts because of performance issues. According to below from http://docs.moodle.org/dev/Cohorts it reads to me that this should be possible but hasn't been implemented.
"Cohorts are designed to replace course category enrolments because the new enrolment plugin is not compatible with this."