Creating a Storage Policy Copy with Deduplication vs Creating a Deduplication Enabled Storage Policy Copy

Hi guys,

This might seem stupid but I’m a bit confused by these two documents on the Commvault website that talk about deduplicating policy copies. 

If I’m getting the below articles correctly, the difference between; 

Creating a Storage Policy Copy with Deduplication 

https://documentation.commvault.com/commvault/v11/article?p=12446.htm

and Creating a Deduplication Enabled Policy Copy 

https://documentation.commvault.com/commvault/v11/article?p=14132.htm

is that the former is created using a Storage Pool (dedup engine exists) whilst for the latter the Deduplication location is not an existing dedup engine (storage pool) but just a local folder on the media agent?

If the latter is correct and I want to use it to deduplicate additional independent copies e.g. Weekly Fulls and Monthly Fulls on independent libraries against the Primary Copy data, is there a  downside to it?

Need some assistance on this.