We will wait and see how the G56 holds up. It has been used in Europe from what I have read and it is rated at a lower torque than the cummins puts out. Mostly has smaller engines in front of it. Basically, it was cost effective to drop the NV transmission since DC could use a in house unit.
Ya, no need for a FASS fuel system on the 3rd gen, no problems yet and I doubt there will be.
It is prob okay to run a edge ez box and that is it. The engine is already pumped up from the factory and has tighter toleances. We will see in 5 years how the motors with tighter specs are holding up to 12 and 24 valves of yester year...
Good luck,
erik