To sign up for a group, you click the group, and then you click "Sign Up". It would be a helpful feature to skip the second step, so that when you click on the group, you immediately apply to it.

• There could be a checkbox/option to enable/disable this feature.
• When enabled, you could perhaps SHIFT-click the group to temporarily disable the feature, so that you could add a note for this specific group application.

This is literally what is implemented right now. Please check out the addon options in the options panel.