Engaging Park with the vehicle not level may exert stress on the gearbox parking pawl, which can be alleviated by activating the parking brake. The parking pawl is not composed of chocolate, to my knowledge, therefore it is unlikely to cause damage unless the vehicle is positioned on a steep incline; nonetheless, why assume the risk? I consistently activate the parking brake prior to shifting the gearbox into Park, to ensure safety.
On a gentle incline, I might refrain from utilising the parking brake to prevent it from adhering if the vehicle remains stationary for several days. The incline of my driveway is little in front of the home, but steeper further away; therefore, I apply the brake before shifting the gearbox into Park on the steeper stretch.