I can just focus on the match up in this thread. But looking at just Luffy: Dressrosa King Kong Gun is the closest to Gai's EE. And he carried way more DC on paper.
Then we simply upscale other characters on the list above DR Luffy.
Great feat but that's a Naruto universe effect. We don't know what this speed looks like in a different universe. We have OP characters moving FTL and being able to move so fast that even precognitive characters struggle to see pass attack patterns.
Although true, It struggled to move around encompassed in ice and Naruto was concern to fall in natural lava. So at the same time it merits limits.
That it true but you also have to remember it's only relevant in the Naruto universe to bend space with his speed. We don't know how it'll do in a different universe such as OP, who can move at light speeds.