Does whatever EFI system you're using adjust timing to maintain idle speed? All modern stuff does it but I'm not sure about aftermarket EFI. When it drops into gear it should add timing to compensate for the additional load.
EFI engines typically have an IAC which is used to control the idle speed. They will also vary the timing to hold a steady idle but this is a race engine with a special throttle body that doesn't have an IAC. The high idle speed is required due to the big cam. It barely runs at 1300 RPM, doesn't smooth out until around 2000 RPM. The EFI goes into closed loop at 2500 RPM since it can't control the engine below that.
