In order to collect GPS data on a portable, the GPS device must be opened.  This usually powers on the radio so it can begin aquiring a satellite fix.  The GPSOpen function does this in an in-prompt script, and the GPS Tracking settings can also be configured to power on the GPS radio.

However, other than powering on the GPS radio, there is no other interaction between the GPS functions and the GPS Tracking.  For example, you must still call GPSOpen before calling GPSGetPosition, even if your GPS Tracking settings are set to leave the radio powered on.

Using the GPS Tracking settings to power the radio does have one benefit for the GPS functions.  By keeping the GPS radio powered on, the radio can maintain a fix so that the calls to GPSOpen/GPSGetPosition can return a fix immiediately (if a fix is available).  Otherwise you will have to wait for the GPS radio to aquire a fix, which can take several minutes.