Custom Quod Libet plugins.
The plugins have been tested using Quod Libet 4.1, 4.4, 4.5, 4.6.
This plugin allows exporting saved searches as M3U playlist in batches.
Beware that due to the lack of an efficient way of getting the case-sensitive name of a file on Windows, performance on that OS is abysmal (a thousand times slower or more).
This plugin truncates a playlist to a size in MB by removing random songs.
Warning: The original playlist is modified by this process. Make a copy if it's important.
Obsolete, Quod Libet now features this out of the box.