I must apologize, this seems to be my mistake... the file silence.wav was accidentally rendered with "force WAV" on the render option, making it an invalid WAV file (>4GB but regular WAV headers). If you do this with a legit wav file (such as
this otherwise very similar newsilence.wav, also in a zip file for downloading) it seems to open fine.
The "corrupt" original version does seem to open fast/fine on windows, but not on linux, so maybe there is some improvement that can be done there, but it seems like less of an issue than I thought.
Sorry for the time-wasting!