Good Morning JT,
Just read your statement... There is no general advantage in scheduling a BFL takeoff as, on most occasions, the RTOW improves if the takeoff is unbalanced.
By scheduling a BFL takeoff you can avail of the speeds provided in the aircrafts FMS, therefore cutting down on crew workload. I would call this a great advantage of BFL takeoffs.
Engineer, the ratio that you are looking for on newer Boeing aircraft is I believe 0.91.
Mutt.