P. Birken wrote:
... However, I think some more visibility of this stuff would be useful. A nice compromise could be to include all flaggings and removal of flags of higher level than sighted into the history and the recent changes. What do you think?
It seems to me this is not really needed. Normally this case would happen when a reviewer is correcting himself, as after he accidentally put Quality on the wrong revision. It's appropriate that the revision history simply show the current thinking on the state of the revision (which it does).
If the lowering/removal of the Quality rating is due to a conflicting assessment by a different reviewer, then it should be noted or discussed on the talk page. The change information is available in the log, and needn't also be in the history. (It does add clutter to the history, and is inconsistent.)