Ability to allow Users to self register for some ILT Enrollments and not for others

Summary

Is there a way to allow Users to self register for some ILT Enrollments and not for others

Content

We have product training that we provide for external people where we can not allow for self registration for an ILT Enrollment.    We are starting to provide the ability for internal people to enroll for certain ILT enrollments.   I know you can select that feature on the enrollment,   However I think that you either have to turn on that ability for all people from a rights standpoint or to none of the people.   Just selecting that within the enrollment does not stop the people from seeing and attempting to self register.