I agree with what you said about liberalism, but I think you're off the mark with regards to left-libertarianism. It's a disparate label, but I can't imagine any of these schools of thought showcasing "the desire for a robust and efficient free market" the parent comment calls for.

Liberal markets + social safety net sounds like garden variety Nordic model democracy to me. The term "left-libertarian" is usually ascribed to groups like Catalonian anarchists or Zapatistas.