Can I delete the original m4b from /assets after the readaloud is built, or hard-link it to save space?

I'm importing epub + m4b pairs from an external drive and ending up with two copies of every audiobook plus the readaloud chunks, which is eating a lot of space. I want to know whether the readaloud keeps working if I delete the source m4b out of Storyteller's assets folder, and whether there is a way to have Storyteller reference the original file instead of duplicating it.

Resolution: Yes — once the readaloud has been created it is self-contained (the audio is embedded in the EPUB 3 media overlay), so deleting the original m4b from Storyteller's assets folder does not break playback. To avoid the duplicate in the first place, set the import mode to "hard link" instead of copy, which makes Storyteller link the file rather than copy its bytes. Hard-link import only works when the source folder and Storyteller's data directory are on the same filesystem — note that separate Docker bind mounts of the same underlying volume still count as different mount points and can fail. If you keep copies, there is also a "Delete cache files" action per book for clearing the transcoded intermediate audio.