Most TMCC locomotives use the PGM/RUN switch to lock out direction changes in conventional.
I've had a few K-Line cruise engines come through, and I own a couple as well. I've been successful in setting them to run properly, but it took multiple tries. There are a number of different techniques that claim to be the "right" one, so I just go down the list. Since there's no official source of info, at least none that I'm aware of, I collect whatever tips I can and try to sift through them.
GregM, the step 5 is in several references, I don't know that it makes a difference or not. It would seem that the engine should already be selected...