Hello Steve
Playing around last night and might of discovered how the extra styles seem to be getting added.
My method of working is to copy & paste before editing on smaller documents.
I end up with a couple of documents but being able go back if need be is worth the clutter to me.
The document that gets something pasted in gains either a new Body Text or Default Style with the pasted material.
When you delete the text that caused the extra style to be added it does not delete the style.You have to manually delete the freshly added style.
Have found a couple of times it took twice to get the deletion to sick.
This only seems to happen with documents copied within Storyist on the iPad.
Bringing in a document from another app does not seem to add extra styles.
Phil