As I've administered Confluence for clients I have wondered and have also been asked if there is a way to handle Confluence space permissions in bulk.
I understand there is no way to do this out of the box, so a 3rd party tool would be considered.
Ideally, this would be handled like Jira: a template could be set up with space roles, and the template would be applied to a set of spaces. The role memberships could then be set for projects.
Alternatively, it would be great to be able to bulk set permissions for an entity (group or individual) so that way a group could be granted the same permission to X number of spaces with a single action.
Really, anything to reduce the manual effort involved would be great. Something that would not have a steep learning curve would be ideal.