Can you share a few more details about the feature. is it just two buttons (import/export).
Personally, import seems a lot more valuable than export. One (import) or two (import & export) buttons would work.
What happens if you were to owerwrite existing etc?
Display an error message e.g. "5 bangs conflict with pre-existing bangs and could not be imported". It doesn't need to be fancy IMO.