Click the new Scene Settings button on the toolbar to display the Scene Settings dialog. It allows you to set both the transition time and delay time for each scene. There is also an input field to set the frame rate. So, all the scene settings can now be updated from a single dialog.
Settings are saved as soon as the textbox loses focus. The bell will beep to indicate the value changed.
The dialog stays in sync with the model. If you change the name of the scenes, add them, delete them, reorder them, etc., the changes are reflected simultaneously in Scene Settings dialog.