> please ensure that there's still a 20px margin between right-edge of toggle and edge of card

Will do, though please let me know if you'd like the round part to be 20px from the edge or the bar (behind the round part) to be 20px from the edge.  The round part slightly overhangs the bar part of the control (so the edge could be with or without the round part present). 

Oh, and if it helps, I like the look of the control with the round part being 20px from the edge of the card (so when it's on the left, the bar part is about 22px from the edge). If you're ok either way, this would be the way I'd choose.

 Issue 646292  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9b19640f013ef467905582bde87a8f0090be694b

commit 9b19640f013ef467905582bde87a8f0090be694b
Author: dschuyler <dschuyler@chromium.org>
Date: Fri Sep 16 23:45:35 2016

[MD settings] Move toggle button dot slightly

This CL moves the circle/dot part of the toggle button slightly. It also adjusts the shadow and translation. These
adjustments are needed for the compact toggle button.

BUG= 646003 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2344083002
Cr-Commit-Position: refs/heads/master@{#419330}

[modify] https://crrev.com/9b19640f013ef467905582bde87a8f0090be694b/chrome/browser/resources/settings/settings_shared_css.html
[modify] https://crrev.com/9b19640f013ef467905582bde87a8f0090be694b/chrome/browser/resources/settings/settings_vars_css.html