The gen3 sees more problems than everything else because it moves so much more oil. It sucks the res dry quicker.... it overruns the IPR quicker, if you have any electrical issues, it's going to vary in pressure farther, so on and so forth.
That is why people see the res go dry more often with gen3 setups. The res may alllllllmost be doing it with say a dual 17* setup, and if so, a gen3 on the same truck would fire..... slow down and die. It's no more complicated than that.
As for running spill oil to the charger directly. Hell no....
The oil quality is THE worst that you could possibly give the charger on one of these engines, period. Secondly, the outflow volume would be varying dramatically. Hell, at a high rpm liftoff you would probably EXPLODE the hose running to the charger when the volume VASTLY exceeded what the cartridge could flow and the pressure went off the charts, headed toward ICP pressure. If the line didn't blow, I would bet you would see blown turbo seals in relatively short order after a few hard pulls and lifting at high rpm. Lastly.... at full throttle, if the IPR duty cycle is relatively high, you may starve the cartridge as the spill oil volume would be very little.
Don't ever do it. Big negative IMO.