Tubeo.com review for Google & YouTube

Hi, I've successfully added the app to my shopify account and everything works perfect. Great work ! I'm now looking to add multiple feed based on each market (belgium, germany...etc) but can't find the option. I've read in the comments that you are going to extend this during the next month ? In the meantime i saw a workaround but don't understand how to do this "You can add countries to your existing feed in Merchant Center by editing the Content API countries." ? Thank you in advance for your help.