First, thank you for your work. Really cool project.
I would like to report that lzip only show compression progress in single-thread. The behaviour is different for multithread.
When I try to use plzip or tarlz (-vvv), it shows just the files that are being compressed. And when is done, shows the final status. But nothing else in the middle.
Also noticed that in multithread is not using all CPUs, but not sure if is normal or not...