Just an update, but I received my letter of rejection from the USSS today. It's fine with me: I'd already decided that it'd come down to either me rejecting them or they rejecting me.

I sent out two more applications to police departments in Indiana (five total so far). The state requires a polygraph as well, so if anyone's interested (and if I make it that far in the application process for any of the departments), I can post my experiences in that regard later on.