This paper aims to extend the BML method proposed in Wang et al. [22] to make
it applicable to more general coupled nonlinear FBSDEs. We interpret BML from
the fixed-point iteration perspective and show that optimizing BML is
equivalent to minimizing the distance between two consecutive trial solutions
in a fixed-point iteration. Thus, this paper provides a theoretical foundation
for an optimization-based approach to solving FBSDEs. We also empirically
evaluate the method through four numerical experiments