Set Output Video Defaults (Possible buggy behavior?)

When I'm working with both EXRs and video previews I need to keep changing between them.

If you change from EXR to FFmpeg Video it defaults to .mkv.

If you set it to .mp4 and edit the settings, whenever you come back to EXR and go back to Video it goes back to the default .mkv

The behaviour feels like a bug because there's no reason for your settings to be reset.

What really would be amazing is if we could set the defaults for the video export forever. But I'd be happy by just being able to preserve the settings from Video > EXR > Video.