The problem with that is I can only tell when we are entering guidance mode if the gps window is visible (which ususally isnt the case if we are looking at another module in our front end). If I suddenly imagine some other method to detect this then ill implement it. However, its not high on my list of priorties right now.
Also, I asked this but am not sure if you plan on implementing. The idea is that anytime iGuidance switches to the "guidance" screen, an event will be raised so that we can switch our front end temporarily to GPS mode. (Then after the guidance screen goes away, it'll be switched back to the previous screen). A Girder event would be great so it's not front-end dependant.