Flush Configuration forces a renew of "meta data" for Clarity Studio/Lookups (items you might find in a content pack).[left]
[left] Useful in a Dev. environment where configuration is changing, not as useful in a Prod. environment where the configuration is expected to be stable. Changing the query behind a Dynamic Lookup sometimes has no effect until you 'Flush Configuration' for example.[left]
[left] NSA is used to change properties.xml level settings - I don't think flushing has any affect on these (my opinion, not fact).[left]
[left]