The Archive.org ID identifies an Internet Archive item, i.e., a file or set of files. It doesn't identify specific books — an item can contain multiple books, and it's common to have multiple items with the same book
 
According to the Internet Archive Metadata, the appropriate way to identify books is by using Open Library IDs, which BB already supports.

Note that I'm not suggesting this identifier be removed, it is useful to be able to add a link to the IA, especially official/semi-official collections. But when we have external links, IA identifiers should be converted to links — because they're not actually edition IDs. We should have downloading and borrowing external links for IA and other libraries practising “controlled digital lending”