We define SHOW_ALL_PAGE_SIZE constant in report/participation/index.php, tag/manage.php and user/index.php, but we define a value, this affects big courses even with
MDL-49963 integrated. I imagine this could be a problem for MOOCs. I ignore if it is a problem for tag/manage.php (I doubt it) but at least for user/index.php it is.
If we want to show all we shouldn't set the limit in https://github.com/moodle/moodle/blob/master/user/index.php#L491