So you mean, that I need to give that user/role e.g. the global modify_task permission so that I can then add a special permission modify_task for the task?
If I do that, the user has modify permissions on all tasks, as I gave them the Super permissions for the group “All users” where I added all users.
I did this because I wanted that all users can always see all objects and no one creates a second task/target/… that already exists. So all users are also member (except the Admin user) are also member of the role “Observer” so that they get the global get_* permissions.