civicrm.settings.php.tpl (template) shoud allow to set a CIVICRM_SITE_KEY when generating the config file (for Aegir)

In templates/CRM/common/civicrm.settings.php.tpl, the site key is hardcoded to null:
define( 'CIVICRM_SITE_KEY', null );

For Aegir, we would like to generate it automatically, so it should be a variable:
define( 'CIVICRM_SITE_KEY', '%%siteKey%%' );

Places (that I could find) that check the siteKey in the code test "if ($siteKey)" and that the length is more than 8 characters, so even if it gets set to '', it should not cause security issues.

Another option, imho, is that CiviCRM could generate the key during install. Would it be a security issue? It would make it one less configuration step for people who configure CiviCRM (without Aegir/drush).

Thanks,
matt / bgm