Require License Key to update plugins?

We are using premium plugins in our themes to provide advance features to our buyers together with ease of customization. Most of the users ask to provide license key for these plugins. 

We buy extended licenses of these plugins and every license comes with single purchase key which can't be distributed to every client.

Whenever newer version of any plugin is released, we embed that updated plugin in our themes and make our theme compatible with this latest version. 

The new version of the theme is then updated to themeforest and an email is sent to all the buyers to let them know about the new version.

 In some of our themes, we have integrated auto update system and the buyers do see a notification to update the plugins. 

We ensure every buyer that all features of the plugins are available in the theme and there is no need to buy extra license for these plugins.

 So please ignore the update notification in the dashboard and continue working on your website. Always update the plugins when we provide the latest version of the theme.