I just took a look at videos you sent. Thank you for those.
I am not sure how much paced feeding will have impact on him, except making additional frustration. He is already on slow flow teat. If we put medium flow teat he gets upset a bit. So, he is already more keen on slow flow.
I think he prefers his bottle because teat is firm (unlike my breast) and gives him stability, and flow is constant. No let down reflex to suprise him.
And he is pacing himself on bottle. If it gets too fast he moves away. And I can see him making pauses. Or somtimes he just sucks without really drinking.