I did have another look at the day-to-night mode switch. The following patch at least ensures the map mode is updating everytime one returns to the map from the settings (main) menu or the preferences menu (in map browser mode). Same goes for navigation mode, and for starting/ending navigation. WIthout it, I believe one has to restart the application (or change the day/night settings specifically) to get the map changed.

Still no update during navigation.

Patch: http://paste.debian.net/179280/