Chrome args and prefs don't seems to be work in protractor conf

Need help with below issues. I have work around for issue 1 so any tips on issue 2 would be great:

1. 
   

   --start-maximized won't trigger full window so my current work around is adding below line in beforeEach function:

   
   

   
   browser.driver.manage().window().maximize();      
   
   



2. 
   

   Trying to download file to default directory but the file is just going to download folder on my C drive instead of /tmp/downloads (on another drive).

   
   

My config:

capabilities: {
    'browserName': 'chrome',
    'chromeOption': {
        args: ['--lang=en', '--start-maximized'],
        prefs: {
            'download': {
                'prompt_for_download': false,
                'default_directory': '/tmp/downloads',
            },

        },

    },
},

As for download, I'm currently using solution from here.