Laser-based additive manufacturing (AM) is considered a very promising technology as it provides flexibility in design for complex structures and minimal need for post-processing. The current optical system used in Laser-based AM is limited to a standard Gaussian intensity distribution, a circular spot shape, and has limited size tunability. We investigate two design methodologies to dynamically change the standard Gaussian intensity distribution of a high-power laser beam into a top-that distribution with a circular or square footprint, and to tune the spot size via mechanical translation of freeform optics in the beam path. To this end, either longitudinal or transverse movements are used. The two designs are simulated using VirtualLab Fusion software. We compare the achieved spot shapes, sizes and intensity distribution obtained with both approaches, and we provide future perspectives towards further optimization.