That comment was way off topic. I think the feature described here has value as does T1460. I'll be looking into helping implement T1460.

I agree with everything you said here :)

This was prompted by me thinking about how to measure the effectiveness of code reviews, then realizing that not only is that difficult with the free-form approach Differential takes now, but it actually makes it harder for everybody involved to figure out what's going on. This is particularly true on hairy patches with lots of back and forth in the review cycle.

I was just looking for something like this.