If memory serves me right, some very good P1 pilots have experimented with changing these settings and have NOT seen any effect.
Go to this link and do a search for GPS Mounting, etc. and you should find these results.
http://www.rcgroups.com/forums/showthread.php?t=1774685&page=2981
I've flown P1 (v1.1.1) for several years and have never changed these settings.