TLDR: please CC reviewer in your feature bug as early as possible, it will help estimate the time & resource.
As our experience of maintaining settings app, we usually found there will be a lot of review requests when the code complete date is closing. Due to the nature of Settings, we reviewers are not likely familiar with all kinds of varieties. So if you have feature bug in hand, we hope you could do us a favor to CC your target reviewer as early as possible, so we can manage our time to check the related context & UX specs early instead of stuck all review&related work at the end of the date.
So if you are developing new or revised setting panels, please put me (:gasolin) in CC list. Thank you.