The WD19DCS provides a maximum output of 210W when both USB-C ports are used simultaneously. Therefore, even under the assumption that the Pro Max supports older docking stations, it still demands 280W to function properly. Without this, you’ll experience a performance downgrade and see a warning screen when you boot up the system. In the worst-case scenario, if the Pro Max model only recognizes a single cable input, then your WD19DCS will function as a WD19S and your system will receive only 130W from the dock (Yes, in this case, you definitely need a 280W psu connected in parallel.).