Can Auto Actions trigger on an arbitrary Joomla event?

When setting up an auto action, it looks like you could put an arbitrary event as a trigger instead of selecting one of the events in the dropdown. Is this correct?

CB Auto Actions can act on Joomla events. Simply prefix the Joomla event with joomla_ and add it to the list of triggers. The triggers input is a Tags field so yes you can add additional triggers to it.

Thanks!!!
I've done a quick implementation of this, and it seems to solve a long-term problem I'be been wrestling with. We have both paid memberships and ones based on work hours, which we have a custom component to track. I haven't been able to figure out how to renew memberships from the custom component without a manual step.
This seems to do it, I just send a trigger with the plan ID and do a renew action (skipping some stuff, obviously).
It may not work in all cases, but I think it will reduce the manual processing significantly.
I have to commend you for the clarity of the documentation on this. 

Follow on question. If the action tries to renew, but it can't for some reason, is it logged anywhere?

CBSubs might log it within CBSubs > History Log, but CB Auto Actions itself does not keep an error log.