@gangleri
This plugin solves only one purpose, for which its built, i.e. allow the use of shortcodes in widget using “Shortcode Widget”.
Adding some default shortcodes will simply increase the size of the plugin, and I don’t think most people using this plugin would need that functionality either. So I’d like to keep it simple the way it is.
About using multiple plugins, there isn’t any performance impact if you use this plugin in conjunction with other plugin to provide you with a shortcode that you can use in ShortCode widget and I’d say, that is the way to go.
If you want, I can simply go through a few plugins like that and provide you with the one that is written optimally.