That busbar looks awfully big for 35 A. Having rigid busbars connect to PCBs can lead to a lot of potential problems. Differential thermal expansion between the copper and the PCB can cause a lot of stress on the interconnection, which can lead to failure over time. I use flexible wires for up to around 70 A, and even going beyond this is easily done by using multiple wires in parallel. Wire with high temperature insulation can help buy some margin here, 125 or 155 degree rated XLPE is a good match for the temperature handling of normal PCB materials. Busbars are viable for higher currents, but need to be designed with flexible sections to limit strain in every plane.
The connection between the insert nut and the board itself can easily be designed to handle 35 A. Make sure the whole current path is as wide and short as possible, and increase the copper thickness in case you need more margin in your design. Skip the thermal reliefs if practical, that way your wire can help heatsink the interconnection and plane.
Edit: I just noticed that the PCB itself will be compressed by the screw and the nut. PCBs will creep at higher temperature under compression, and once you lose compression of the joint then you also lose the integrity of the electrical connection. Consider either pressfit terminals where the PCB isn't compressed by the screw, or soldered threaded terminals.