[Ipiano]

I noticed the same thing, and likewise, we use it heavily; primarily to define our autonomous.

Our team was privileged to be a part of the control systems beta test, and, as the head programmer, I can say that the widget WAS implemented... or at least planned. The widget that existed didn't work very well. Additionally, there was the option to change widgets to different types after they were added, something that is stated as a feature in the tutorial on screenstepslive.

These two things lead me to believe that we do not have the final version for our use and that a new version will(hopefully) be released.

Until such time, the only thing I can suggest is to send a string variable to the SmartSashboard and then modify it on the dashboard and use a "Get" method to save it on the RobotPreferences in code.

--UPDATE--
A more viable workaround is running the old smartdashboard alongside the sfx dashboard with just the preferences widget visible. It works.

Also, I'm going to try writing a widget for it myself. All it needs to do is ftp the robot and modify/read the wpilib-preferences.ini file. If that goes anywhere I'll post it to GitHub