[V-2]

> I didn't say this affects branch diffing, but rather trawling through history on a single branch.

Exactly. What's the point of all the "oops, a typo" or "applying code review remarks, part III" commits. Just rewrite. This is the workflow you get eg. with Gerrit.

[convolvatron]

choosing between readable commits and mergeable history is a false dichotomy - just because git imposes that choice doesn't mean its fundamental