j.t.
Unless the sector is terrain benign, if I am wearing an ops eng hat I'll run the entire sector through the number crunching.
And, I hope you will be applying FAA Advisory Circular 120-91 or its equivalent.
Advisory Circulars
What I find so frustrating about the for-hire performance and engineering companies is that they still do not offer a OEI rnav flight path option.
That, of course, begs the question of when or how the OEI rnav path gets loaded. I don't want the F/O heads down doing that at KMMH (Runway 27) for example, after an engine fails at rotation.
But, those smarter FMSes that have a second flight plan option, it can be pre-loaded where appropriate.