When usebnodes=true and output format is ntriples, the converter creates bnode ids such as _:binstance14, which are duplicated across files. If the user is combining output from multiple files, different bnodes will have the same identifier. Note that for bnodes created even when usebnodes=false (e.g., for Providers), bnode ids contain the record bib id as a substring, as well as an integer value that is not repeated within the same file, and are therefore presumably distinct across files. This technique for creating bnodes ids could be applied for the additional bnodes created when usebnodes=true (e.g., for Instances) to keep them distinct as well.
On further investigation, this should not be regarded as an issue with the marc2bibframe converter, since the RDF spec specifies that blank node ids are locally scoped to a file.
When usebnodes=true and output format is ntriples, the converter creates bnode ids such as _:binstance14, which are duplicated across files. If the user is combining output from multiple files, different bnodes will have the same identifier. Note that for bnodes created even when usebnodes=false (e.g., for Providers), bnode ids contain the record bib id as a substring, as well as an integer value that is not repeated within the same file, and are therefore presumably distinct across files. This technique for creating bnodes ids could be applied for the additional bnodes created when usebnodes=true (e.g., for Instances) to keep them distinct as well.