In the same way that you get dispatch remarks stating “Payload limited by MTOW/MLW”, it would be good if it could automatically find the payload limit to be able to complete the flight for flights that generate the “exceeds aircraft range” warning when the payload is randomised, but do not generate that warning at zero payload.
For example, EGLL to YPPH in a B789 generates the aforementioned warning with freight set to none, but passengers, payload and ZFW set to auto. However, if you set the ZFW to minimum, it has more than enough fuel to complete the flight. There must therefore be a ZFW between the two where the block fuel required is exactly the same as the maximum fuel capacity.
To me, it would make far more sense for SimBrief to calculate this if the weights are set to auto, and limit the payload to that corresponding fuel capacity. It would then only generate the “exceeds aircraft range” warning if the block fuel required is still higher than the maximum capacity when the payload is 0.