On the ACP index page there are several tools that admins can use to run basic commands on the forum like reset board stats, purge sessions and purge the cache. There's also a template event which allows extension developers to include HTML at the bottom of this list of tools.

However, in the file:

includes/acp/acp_main.php

There is no php events that allow extension developers to tap into the checks done in the file when these actions are being processed.

There is an event further down:

/**

* Notice admin

*

* @event core.acp_main_notice

* @since 3.1.0-RC3

*/

$phpbb_dispatcher->dispatch('core.acp_main_notice');

This event, whilst it does allow developers to run their own custom actions, it means all of the previous checks done for the built-in actions have to be redone like checking the action, checking if the user has permission to do said action, check if the form has been submitted (so the action can run) and checking if the action is being done via ajax and so on...

There should be a more php events in this file to make it easier on extension developers that want to specifically add custom actions from the ACP index page.