I don't know how many times I've started to export a timeline while forgetting to enable/unmute a track. When you disable a clip, it turns dark, so I tend to use this INSTEAD of track disable/mute these days.

You have a great visual cue to show a disabled clip, and a great cue to show a locked track. Shouldn't you also darken the entire track to show the track is disabled or muted? This seems like a really obvious behavior to me, and an easy change to make.