Trade offs sure but design and scaling need to be considered _before_ the code review. Maybe an architecture review of sorts? Once you hit code review it's a little too late to reconsider design and scale unless it's a serious issue.
> mentor others
Mentoring is mostly outside of a code review. Sure it can help with that but I don't think that really counts. IMO anyway.
Strongly disagree, at least for remote teams.
Working remotely, I've personally found code reviews to be a great way of mentoring less experienced team members.
I also encourage junior team members to review code of more experienced team members.
For big changes, we discuss proposal/API/code reviews as a team.
I've had several people provide feedback that they've learned a lot from reviews like this, and honestly I wish I'd had this kind of mentoring when I started out (I was basically a one-man cowboy-coder for the first 5 years or so of my career).
I know mentoring can be seen as a chore for many, but it can be seriously rewarding too!