In order to prevent self heating errors,current shunts are typically 50mV full scale for 20A. But for 200A , I suggest 5mV drop for 1W dissipation. Then use low offset high CM Op Amp or special Current sense amp,
Try to work around this instead.
This means 250uΩ using wide strip for low inductance and good heat dissipation. The current injection points ought to be at least the conductor width longer on each side, than the V sense points. Use the ampacity tables for copper weight and track width and multiply by 3 or more in width.
You can even use cheap steel flat bar instead of Copper with a smallish 1" length.
I suggest threaded bolts and suitable spade lugs for 200A with washer to busbar to increase contact area to match or exceed width. This should get you down to 50 µΩ contact resistance on oxide free gas tight flat contact with suitable torque with fine machine threads , then mounted to PCB , then tiny screw tap calibrated hole span for 500 uV using a precise 20 A DC load current etc. or any current and compute V/R ....From then on use an IC for 5mV full scale high rail current shunt like used in automotive or DIY with high CMMR using twisted pair sense lines. This will likely need to be chopper stabilized for zero Dc offset.
A piece of stainless steel or zinc steel is way cheaper than a 200A copper PCB.
btw 200 mV at 200A is a 40 Watt heater, not an ammeter