Here is the problem: I can't seem to be able to make use of the Vossloh's slow speed control. Even after learning that it only works with the gearing set to shunting, not line, I still am having a problem making it work. The basic problem seems to be that cruise control will not engage unless you have positive throttle- but even the smallest bit of throttle sends the speed higher than a targeted 3-5 km/h faster than you can engage the CC-- and since this is a true cruise control, not AFB (i.e. it only controls throttle, not brakes), it doesn't slow down to the target speed once it does engage. What am I doing wrong here?
Using it with a light engine That is for when you have a train on the hook that should be loaded/unloaded with a constant speed. It is not used as a cruise control in the shunting gear. Makes really less sense to use the cruise control at all with a light engine.
With our shunter we approach with tiny direct brake pressure applied, that helps for controlled approach irl, see if that works for you
There are two ways to approach the cars/coaches. First of all, before you even bump into the vehicle, normally you should figure out if those cars/coaches are somehow secured with handbrake/praking brake or air.. which is kinda difficult in TSW in some cases. Then try to bump into it with 1-2 km/h mostly, 3-5 km/h are pretty hard. Approaching those, either with bit applied direct brake or just bump into it and then power it up afterwards. In both cases the buffers should slightly pushed into it, to make coupling easy even in a slight curve.