I've not used the module but from having a look at the project page text, the module doesn't seem to be production ready. ("This is an initial port of the module ready for testing.") That said, it might work in some cases, but I'd however recommend to post a report in the module's issue queue, hoping that the person who ported the module will have a look at it.
FYI: There's also an open issue in the queue with the suggestion to bundle the library with the module, cf. https://github.com/backdrop-contrib/plupload/issues/4.