Well, one of your difficulties is that you only saw only neurosurgeons and not spine surgeons. Generally, neurosurgeons tend to think somewhat differently than spine surgeons.
Nonetheless, it has been demonstrated that your own bone works better than allograft bone. If the “cage” is really an allograft (designed as a spacer as a cage would be), then the surgeon who will use your own bone should have a better fusion rate. In either case, they both should be using pedicle screws and I would hope they would use the O Arm to insert these screws.
Again, a third microdiscectomy is something I would not consider as the reherniation rate is high and the root cannot tolerate further compression without injury.