No option to preserve clip transparency while reversing video

I have an intro animation I made in Blender that has a transparent background and different objects come into frame from different directions, and then leave move around on screen before leaving to another direction. The pacing of the animation makes it good for an intro, but I’d like to use the same clip, reversed, for an outro.
The reverse feature in the properties tab works well, but none of the video options as far as I know preserve the transparency of WebM. I imagine this could be implemented either as a transparency check-box or by matching the codec of the original clip.