Today I tried the McClure service part 1. A bit tp my dismay the train started rolling backward right away. Of course it was not setup at all. Independent brake released and no handbrake. I think this should not happen. When starting a service we need a well defined and stable game start. EDIT: workaround: As soon as the scenario starts, set the MU valve to lead or dead and the cutour valve to freight. This makes the train stop moving. But now the PCS is tripped. So set the train brake to emergency,setup you engine as it should be, including the independent brake. Now you can release the train brake, set the reverser forward and get off.
Same issue for part 3 of this sequence. This also happens to engines that have no service assigned. I wanted to hijack one to do some coal loading, and got a run away engine straight away. Probablay it also may work if you apply the hand brake before sitting down.