[GordonS]

Code formatting tools/linters and static analysis tools can deal with the bulk of this before it even gets to review.

For the small stuff that remains, ideally the reviewer can fix it - the reviewee is probably back in flow on another task, and it's irritating to have focus broken for inconsequential things.

As a side note, I like how github implemented this as "review suggestions", where the reviewer can make small changes inline and the reviewee approves them with a button push.