At this point, Agenda keeps a complete history of your changes, so it does not reclaim space when you delete things. We have ideas for improving this in future.
Just to confirm, let’s say I have a project that takes 50MB of space. Will the space be released if I delete the entire project and remove it from the trash bin as well?
My ultimate goal is to cut down the iPhone storage and iCloud space taken by Agenda. I originally tried to replace full-size pictures with compressed ones but that doesn’t help.
If you delete a project, move it to the bin in Agenda and empty the bin, it will release and reclaim all space the project took (which is also why you can’t undo the emptying of the bin), it will also remove the iCloud space the project took.
Note also that there is often quite a delay with iCloud storage numbers. It can take quite a long time for it to update in the Settings app. So even if you do reduce the size of a project, it may not show up in iCloud as reduced for several hours.