Consulting work for counsel is only useful when its boundaries are explicit. Scope confirmed in writing at the outset protects counsel, the engagement, and the credibility of any later report.
Every observation should carry its evidence reference and its assumptions. Observations that depend on production completeness should say so, in the document, at the time they are written.
When additional production changes an observation, that change should be visible in the version history rather than quietly absorbed into a later draft.