Our guys really appreciate the “Copy from…” feature, as it makes swift work for localizing modular content blocks from English.
However, we have a use case where it would be very helpful to copy from a different locale than the primary. For example, we often have country-specific content for an en-CA page (English-Canadian) — different from the regular en page — which we then want to localize into fr-CA (French-Canadian). In this case, the “Copy from…” feature does not help at all because it will only let us copy from our English-US locale which has very different content.