Man, I just wrote them in my comment, I know that. What am I saying that what is difficult in technique is the number of times it is used, this is obvious in the plot. As the technique says, "Not every Sorcerer Jujutsu is capable of using", at no time is it said that they are not able to perceive the attacks. How do you think they count the Black Flash? If they didn't feel the technique, they wouldn't be able to count. The plot makes Kento amazing for knowing how to use Black Flash 4 times, if the plot wanted to convey the idea that what is limited is to perceive the attack, they would make their moment noticing the seconds, not using it multiple times
It literally means nothing. Gojo can't use it more than 4 times doesn't mean he doesn't feel the technique, it means he's not an excellent user of the technique
The meaning of the sentence is that she has a high-level perception capable of feeling the seconds, that is obvious in the sentence. And I really don't see the amount of contradiction, everything indicates that what is difficult is the number of times to use it several times. Kento himself says that this is what is difficult
445m/s