Returning them as part of the instance object could be problematic, as there could potentially be 1000s.
Some of the persistence providers do store them, but there is no API to retrieve them currently... this is a gap that should be addressed.

Thanks Daniel.

I am in the middle of making changes to add additional columns to the ExecutionError table:

• Type (ex.GetType.ToString() optional
• Message (already exists, ex.Message)
• Source (ex.Source) optional
• StackTrace (ex.StackTrace.Trim) optional
• TargetSiteName (ex.TargetSite.Name) optional
• TargetSiteModule (ex.TargetSite.Module.Name) optional
• HelpLink (ex.HelpLink) optional

I am also adding an additional ErrorCount property to the Workflow instance class.
A new method will be added to the IPersistenceProvider to fetch the errors for a given workflow/s.
This will have feature detection, as not all providers support persisting errors, therefore I will also add a SupportsPersistingErrors boolean property.

I will be adding tests for these changes also.

Should have a PR early next week.