I see that animated video previews can be made by forcing an update of all files with a rescan, but can there be a selective forced rescan? I have filtered and selected only video files but still don't see how to forcibly update only those.
Select the files in a file window, then press <Shift>+<Ctrl>+<F5> or hold down <Ctrl> while selecting "Rescan" from the context menu.
See "Advanced Rescan" in the IMatch help for details.