This release adds support for running multiple processes per consumer. I initially made the assumption that this would be done by just passing the --multi-process n option to bin/magento queue:consumer:start, but Magento only uses the value to acquire a lock for that specified value (see Magento source code).
The configuration remains the same, the implementation is just better now and actually starts multiple consumers when it's configured that way.
I also tweaked the release profile, reducing the binary size by ~80%!
Full Changelog: 0.2.0...0.3.0