> there would no clean way to edit/remove/reorder downstream commits Yes, but I consider commits immutable so reordering or editing commits is not a thing that

> there would no clean way to edit/remove/reorder downstream commits Yes, but I consider commits immutable so reordering or editing commits is not a thing that would happen. New commits are appended (either upstream or downstream), and any conflicting changes then of course have to be merged from upstream into downstream.