Hello James,
Thanks for using our plugins and welcome to the forums!
I’m very happy to hear about paying attention to server space. Awesome!
Just like with regular WordPress posts, the images in the image library areĀ not touched when an post / event is being trashed. I have some ideas why it’s done like that…
So normally you need to go into your media library and manually remove the images.
I did a quick google search as your request made me curious too. I found this post on the topic which you also might find helpful.
Delete Images from Media Gallery when Post moved to Trash
Note, that I haven’t tested it, so I cannot vouch for its workings. And I’m not sure how it handles the different image sizes that are created. Nonetheless it might be worth a try. And it is definitely recommended to create a full file and database backup before making any big changes.
Hope this helps.
Cheers,
Andras