Nice thought! I've implemented this, looks good with only hacky part to be those function() selectors,
https://github.com/chrispetsos/prefsEditors/blob/adjusters-pilots-2/src/shared/adjusters/js/magnifierEnabled.js#L29-L32
The adjusters that are supposed to be hidden according to the "magnifierEnabled" value and "moreLess" state are contained in the parent compositePanel (increaseSize) of magnifierEnabled adjuster panel. So, i had to do it that way, looks a bit awkward but it works. Is there any other way i can select some DOM elements from the parent adjuster?
I know this is getting quite complicated and the deadlines are running... I think we should be deciding a way to do this within the next couple of days... Thanks!