I know what everyone is talking about - but I don't really care. Whether or not a single emitter or light produces a square beam is only thinking about the "lighted area" issue with a simple perspective.
Bicycle lighting needs are considerably more dynamic than that of an auto or motorcycle. But even at a simple level - most cyclists understand their lighting needs change with their current speed and current surroundings.
Maybe square is better. But sometimes only a lot more will do.
At least some manufacturers address this issue by employing dual-beam head lights. I know I'm just an old school "Richard Cranium" - but I'm going to use a high powered flashlight to get the "beam I need" when going somewhere fast in the dark.
I'm sure there are some $300 plus lights that just work by changing power settings - why not mention some of those lights?