Why would you waste Simcoe as a bittering charge with all of those wonderful flavors and aromas it provides. That hop is too precious and hard to get to waste it as a bittering charge! You are going to boil most of those aromatics off, anyways. Substitute it for another high alpha hop like Magnum, Chinook, CTZ, Summit, or Apollo. Save the Simcoe for late in the boil. That's my $0.02.