Laser Beam Scanning (LBS) light engines based on two-dimensional (biaxial) resonantly operated and vacuum packaged MEMS scanners, show several advantages over traditional display technologies. Their easy scalability in terms of brightness, resolution, field of view and frame rate makes them well suitable for a wide range of applications including automotive Head-Up Displays (HUD), outdoor displays, 3D sensing and especially compact and fashionable all-day wearable Augmented Reality (AR) glasses. In order that LBS light engines can exploit their unique advantages important challenges must be overcome first. The aim of this paper is to explain the function principle of MEMS based Lissajous laser beam scanning as well as the importance of control loops and optimization mechanisms. Additionally, the resulting opportunities for LBS light engines are highlighted which allows the projector to scale towards the desired resolution, frame rate, field of view or brightness. The achieved projections demonstrating different use cases are visualized by real photographs.