Prune Notifications task

During execution Prune Notifications task following query is sending to DB server:

SELECT notify_id, notify_to_id, notify_sent, notify_read FROM ipb_inline_notifications WHERE notify_sent <= #TIMESTAMP# ORDER BY notify_sent ASC LIMIT 0,500;

1. Why here used "ORDER BY notify_sent ASC"? In case of using InnoDB type of ipb_inline_notifications table this ordering sometimes takes a lot of time.

2. Why limit of 500 is used? On large forums it is not enough to prune all old notificatins and ipb_inline_notifications is growing permanently.

Our current workaround is not to use ordering and increase limit to 50000 in the query above.