Videos exported in compatibility mode don't work in Firefox or Chromium

[presto8]

In compatibility mode, any exported videos are saved as attachments in .MOV format. However, Firefox and Chromium do not recognize this, resulting in "No video with supported format and MIME type found." I used ffmpeg to transcode the MOV to MP4, and then added and it worked.

Maybe "-c compatible" should transcode .mov to .mp4 for maximum compatibility?