Although I haven't tried it, a method for soft boiling is heat water under boiling point, swirl the water with a spoon or other to create , a swirling eddy. Drop egg in middle- the swirl contains the egg as it becomes poached, preventing the whites from exiting to pan edges. It makes sense, I have to try it. The key is not to let the water boil, but keep it just under the boiling point. Hmm.
But a poaching pan is more sensible for more than one poached egg - above method sounds ok for single shots.