An update to Onetastic adds auto save and recovery options to Macro Editor, a new data store function and includes other minor improvements and bug fixes.
Auto-recovery will recover any unsaved macro in case of a program crash. When you open OneNote next time after such an occasion, Onetastic will automatically open the recovered macro and you will be able to save it.
Auto-save and auto-recovery options can be configured from Tools > Options menu in Macro Editor.
You also have an option to display the current auto-save and recovery state on the title bar:
Auto-save and recovery options are available to Onetastic Dev license users.
You can also manually clear the storage for a macro using Object Browser, by right clicking on Local Storage: