Dynamically allocated pseudo-filesystems

> I use tools like lbzip2 because compression is another common operation that is trivially parallelisable.

There are caveats for complession. Block schemes like bzip2 are trivially parallelisable with increased memory usage (which is quite low anyway) as the only drawback, but Lempel-Ziv and streaming compressors in general may take a hit to compression ratio, at least if done without care.