I don't think you are going to hurt anything by running in first gear. I wouldn't have the patience to run in first gear even if I didn't have brakes. I would use 2nd. It will provide plenty of engine braking. I don't see the analogy of running a 13 speed speed in 1st in the high side. The old 13 speeds (before the RTLO series) were nothing more than a than a 9 speed with another splitter in the rear. In 9 speeds as well as 13 speeds, 1st gear in the high side does not fit in the shift sequence. Not using the gear has nothing to do with gear wear. As far as the smell, it is very common for the smell to come up the shift tower. If you are not slinging oil anywhere, I wouldn't worry about it. However, it probably wouldn't hurt to change the oil in the transmission.
