It also has some presentation issues on longhand overrides of shorthand rules. Eg: If I override margin:0 with margin-top:1em, the margin:0 rule is not struckthrough.

Granted, the most accurate way to present that override would be to display margin: 0 0 0 0, with only the first 0 struckthrough. But that deviates from the written code and becomes more difficult to track.