Visible diffs segments not the same length as updated VFX shots,

I’m working on a feature-length horror film. We received a new set of Quicktimes with VFX updates. The new shots mainly consist of color-corrections (i.e. shots being made “darker.”) I’m assuming that the timing changes are being made for the entire length of the shots.

I am comparing the Quicktimes and DX guides for “Anything” and have Auto-Diff on, Visual Delta Threshold set to 100%. Only Visual Diffs are indicated.

The Visual Diffs generated fill most of the timeline, but are typically shorter than the shots they represent (gaps at the head and tail.) Activity in the Delta window is much less than I would expect from the amount of Visual Diffs in the timeline. Is the latter a discrepancy between a real-time process vs an off-line calculation?

Why do the shot length, Visual Diff length and Delta window activity not seem to agree?

I think this might be an issue fixed in MB1.4.x
At time of writing, we’re waiting on a windows fix before we can release 1.4