@drMerry - it already does this. I just haven't updated the plugins index page to reflect the deprecated status for those plugins. It has only been out for a few hours...
@zhw007 - Welcome to MobileRead. Unfortunately I know nothing about proxy servers. The plugin uses the same browser object that I believe is used for metadata downloads, which IIRC is based around retrieving your IE proxy server settings if any. Do metadata downloads work? Perhaps Kovid may have some suggestions on this.