The 'Broader Impacts' section the proposal is a required element for all National Science Foundation proposals (like this one). It need not be about diversity b

The 'Broader Impacts' section the proposal is a required element for all National Science Foundation proposals (like this one). It need not be about diversity but you need to articulate how your proposed work has "potential to benefit society and contribute to the achievement of specific, desired societal outcomes." So certainly it's forced. In the same way demonstrating the Intellectual Merit of your work is also forced (that being the other criteria against which the proposal is going to be judged).