Mmmm ....
Wheeled aircraft ...... should ALWAYS use wheel chocks.
Dick FYI when Agusta designed the AW139 they went to a system where the brakes are independent of the 3 other hydraulic systems and you CAN pump up the brake pressures from the pedals prior to a rotor start .... seems to work well.
Answer ..... trade up to the 139! (Ha Ha)
Cheers