Following up on how to listen to LEX platform events

https://community.skuid.com/t/how-to-have-skuid-listen-to-lex-platform-events-how

and
https://community.skuid.com/t/seeking-deeper-understanding-of-lightning-component-events

Are great.

However I think I must be missing something as Zach talks about event triggered sequences there is no skuid:event in the declarative list of Event Names. So if for custom platform events do we need to set up a listener via code to then trigger the action sequence?

My use case this go around is very straight forward:
Attachment gets added to sObject(it is Attachment so process builder wont work), fires a trigger that publishes event (for skuid) that then runs action sequence ( which closes sliding panel).

Thanks for all the help. Hope everyone is safe and well!