I guess this is gonna be one of those garbage teir stories where consistency means nothing and the level of power and ability shown by the main character is haphazardly tuned depending on the situation.
Dude literally flashed stepped a singular chapter ago but now all of a sudden it takes him 3 business days to cover the same distance in a desperate situation where lives are actually on the line. This shit really pisses me off with manga, you wanna make the mc op from the start but also want scenes where he "struggles" but instead of going through the effort to make it seem even somewhat natural, you just force it in the dumbest and most nonsensical way possible and hope that the readers will just look past it for the sake of your plot that's now riddled with holes. And all for what, a cliffhanger?
It's usually the case that when authors do this, especially when it's done so early in the story, that it's going to be a consistent theme throughout because it just shows right away that they can't write a proper scenario to save their life. In which case, I'm already considering dropping this.