Adapt PCB from Eagle to KiCAD and increase performance from current 80A to 200A with peaks of 400A (specify heatsink for the design).
Theoretically, used MOSFETs (FDMT80080DC, two in parallel) should be capable to handle 200A requested currents if they are cooled properly, but heatsink must be calculated. Also the Würth press-fit elements are already capable to handle 200A in theory.
Probably it would be more safe to redesign the board for more MOSFETs in parallel. In addition to that, the board should be produced with thicker copper plating, currently only done 70µm.