Press the function key allocated to "uncouple" and the loco backs up enough to take up the slack, the coupler activates, and loco drives forward to clear train before coupler releases. Total movement is perhaps 1.5 sleepers, all at a slow crawl.
See earlier posting for pictures underneath and description of mechanical components.
There is scope for fiddling with the uncoupling movement time, speed, and the general speed table and acceleration parameters. These all influence the exact speed and distance moved. But priorities are 2mm models for the annual Expo at the end of June.
The video below shows the loco come to a stop under normal throttle control, then the function key is pressed which causes the loco to back-up, uncouple, and pull clear. This is an improved video, with better lighting and some closeups
(Next back to why the 2mm scale CT DCX 74's sometimes loose half-speed mode, and why one of them is reading back wierd values in its primary CV table. The alternative CV option is proving the way out, but this bug is wierd...).