A new first two seconds is the fix, not a new music bed, a new colour grade, or a longer intro 'for context'. Start talking or showing the problem in the first sentence, put a face and on-screen text on frame one, cut any logo sting, and write a line a real person would say out loud. If you cannot explain the video's job in one spoken clause before second two, the hook is not finished.
Start with three families, not fifteen: a problem call-out, a pattern interrupt, and a specific proof or demonstration. Those three cover most of the work a 9:16 open has to do. Question hooks and wait-don't-scroll lines are overused and often read as ads instantly. Native-sounding, specific, slightly unfinished lines beat slogans. Keep them under 15 words. On-screen text in the first two seconds usually helps because a large share of feed viewing starts muted — a short, high-contrast line that matches the spoken hook, inside the safe zone, under about seven words. Mismatched text burns trust in the same two seconds you are trying to win.
A more realistic avatar will not automatically raise hook rate. Realism helps only when the current face is the reason people bounce — obvious artefacts, wrong age band, or a setting that screams studio. A slightly more realistic avatar delivering a slogan will still lose to a merely decent avatar delivering a specific, human line. Casting and copy both sit in the first two seconds; copy is usually the cheaper test. Run the 3 × 2 batch before you commission a custom clone. If both stock faces hook under 20% on cold with good scripts, then you have a casting or offer problem, not a render-quality problem.