Hi wavemaster -
The reminder was added to the button mapping in response to questions from customer who were not able to locate the pop-up menu with the navigation options after re-mapping the left SpaceNavigator button.
For anyone who may not have followed the history of the left SpaceNavigator button, this is the button that is the equivalent of the 'Menu' button on the SpacePilotPRO and the 'Panel' button on the SpacePilot and SpaceExplorer.
In SketchUp,Inventor,3dsMax,Pro/E,Creo,Maya, NX, Softimage,Solid Edge and SolidWorks this is the button that is mapped to the pop-up menu. Pop-up menu items vary with the application and include options like 'Rotation Center' and 'Speed'. In applications where button mapping is done outside of the 3dConnexion Properties window, the pop-up menu includes 'Customize Buttons'.
To make sure the pop-up menu remained available, in Release 3.13 the software 'locked' a device button to the pop-up menu. On the SpaceNavigator with only 2 programmable buttons, this reduced available buttons to 1. For this reason, in Release 3.14 the persistent mapping was removed - 'unlocking' the buttons that were mapped to the pop-up menu. The reminder remains so that access to the pop-up menu is not unintentionally removed. Of course when you want the pop-up menu you can re-map it to your button. Without some type of reminder, though, there would be nothing to indicate where the pop-up menu went or how to get it back.