Skip ahead to later parts of a recording made using the audio recorder core plugin, without first playing through the whole thing. (You can’t, because the file doesn’t contain cue metadata.)
The ts-ebml package on npm has a command-line tool to make a Chrome webm recording seekable; its Typescript API could be used directly in the audio recorder to rewrite the webm file when recording is complete. The actual CLI implementation is only a few lines, and should work reasonably well even if the recording has to be read back into memory and written out again:
Alternative 1: Use the ts-ebml CLI to copy to another file, then copy back to overwrite the original (since it can’t be done in place in the shell).
Alternative 2: Convert the webm to mp3 with an audio converter or ffpmeg, then manually replace the link and delete the original file.
Chrome has a long standing bug report/feature request to add metadata to the recorded webm in order to make it seekable. They don’t seem inclined to implement it. Maybe we will implement some form of workaround for this issue (like the one proposed by pjelby) if it works on all platforms.
A workaround will be tested in 0.14.3 for newly recorded files.