There is more testing from that channel:
https://www.youtube.com/watch?v=X6RSEU1d-g8
https://www.youtube.com/watch?v=X6RSEU1d-g8
So the problem is not only the latency in Zen2 but the IF bandwidth. Even overclocking a Ryzen 7 3800X to 5GHZ won't help that much!