R915 is not Galaxy S...
neither is R910.
They both are variants of the Galaxy S line.
Some Galaxy phones have not been added to that list yet. So I'll err on the side of caution and say if you do decide to try this, prepare yourself for an eventual bricking and prepare for the worst.
But if you wanna be the guinea pig and try it out for us, please do so! As long as you know what you're doing and are proceeding with extreme caution.
Good luck!
BTW. Cricket is R915. metro's Indulge is R910