We'll get a speed win on a large collection of files with old HDs by using an archive format like PKZip to cut seek time when opening many small files.
But that also increases the potential scope of supporting compression ... the scoping rules for locating parts vs MPD vs file system isn't particularly well-spec'd now, and adding archives would further complicate the situation. Does a program have to search archive table of contents to find any LDraw file, and how would the program know which archive to search?
