No, this is CTS/DCD. Both are inputs, and so will not affect anything else wired to them. It's "shared by" as if you're going to use it for flow control, you don't get it for lights on/cellphone (& vice versa).

We didn't have the pins on the docking connector (and 24 way is the biggest one that (a) we could find and (b) could be worked with by the harness manufacturers) to have full serial docked - the first priority would have been for docking ethernet, really.

The CTS line is there to allow a remote device to throttle the empeg's data flow. There's no RTS, but this shouldn't be a problem as the empeg generally doesn't get to the point of not being able to buffer data :)

Hugo