Gearbox Designer

Will it eventually be part of the engine designer or will it be it's own separate thing when it is released? I always find myself pretending my engines are going through the gears in the manual test mode so will we be able to test our engines with the gearbox? Maybe space can be the clutch, A can be Upshift, and Z can be Downshift, and the mouse can control the throttle? Just throwing idea's out there because I have nothing better to do at the moment.