Original proposal
In this discussion on itwiki, several users expressed concerns about the positioning of the "desktop version" button in the mobile version. Right now it is located at the bottom of the page, which, according to these users, is hard to find and hard to reach (because you have to scroll down to the end of the page).
The proposal there is to place the button somewhere more visibile, e.g. in the sidebar. I think an option might be to move it under "Settings", i.e. similar to what the following code would do on-wiki:
mw.util.addPortletLink( 'pt-preferences', mw.util.getUrl( mw.config.get( 'wgPageName' ), { mobileaction: 'toggle_view_desktop' } ), 'Desktop version', '' );
The link at the end of the page could stay anyway.