You do not have enough power with a 50W machine for clean cutting 1/2” acrylic.
Clean cutting with polished edges means a single pass at just the right speed to cut and polish (as well as using a long focal length such as 101mm).
Your biggest hurdle is the multi pass cutting. You’re heating and reheating and melting surrounding acrylic of the kerf with every pass.
Example of 1/2” cuts on acrylic, one pass, 140w laser: