No, you don't have to burnish PolishGuard. Without burnishing, PolishGuard will cure chemically and leave a matte/satin-finish. If you want added gloss, high-speed burnish with a white pad. 

Consolideck® PolishGuard is a durable, protective coating that dramatically increases the stain resistance of interior concrete floors. This non-yellowing formulation enhances the appearance of standard gray, integrally colored, dyed, stained or color-hardened concrete floors. PolishGuard is ideal for steel-troweled, burnished, polished or decorative concrete and cement terrazzo floors that are exposed to accidental spills of food products, household cleaners and many industrial solutions.