If auto save is added, please make it a selectable preference. I often like to open a file to play with ideas, then exit without saving if the ideas don't work. I'd wouldn't want auto save to make a simple experiment permanent.
Autosave should be set on a timed basis for all files Doodly files so that if and when the platform fails - which seems to happen at random - the work can be recovered. It would be fine to have a preference whether the autosave file is deleted upon deletion or exit without saving. But PLEASE, if the platform is going to be unstable, have an autosave feature. This should have been part of the original architecture.
Just accidentally hit the close button - it asked save or discard. i hit the x on the button thinking it would bring me back to my work and it closed. Just deleted like 3 hours of work. How can you not have autosave!?!