Reed stays locked to his nusa loyalty throughout all choices and missions, there's no changing that about him. The main choices come down to whether you back his mission or side with songbird but his dedication to the fia never budges. Maybe interesting to note that even if you try different dialogue options with him, he'll still justify everything as necessary for the nusa cause. During missions, his actions consistently show this – when things get complicated with songbird, he sticks to presidential orders no matter what.

The real branching comes from how you deal with his unwavering stance, not trying to change his mind. His survival and certain mission outcomes can shift based on your choices, but that core nusa loyalty is basically hardcoded into his character. When you're working through the firestarter situation, you'll see how deep this runs – he'll rationalize some pretty tough calls all in the name of duty.