Callouts are using BOM-ID
You changed this because the correct BOM-ID Info is part of your meta "Instanace Name".
There is no tool inside of the Composer to manipulate those metadata.
Only changing manually is the way.
If you look on the Solidworks-webside and search for Partners, there is one who provide a tool to expand Composer.
Thank you for your reply but I need to find a workaround for this problem. I tried looking for said tool at http://www.solidworks.com/sw/products/engineering-software-partners but I couldn't find what you you mentioned. Could you get me a link to that page?
Search Keyword: Composer
2 Partners appear. 2. Partner is a Solidworks Composer Partner
Darn - I was hoping you got an answer. I have the same need. Please be sure to share if you do find a way or partner with a way around this.