There’s no way to say that gear shift’s amp or super speed amp are more substantial than each other when both of them don’t have a stated multiplier in the first place. The fairest assumption is that gear shift and super speed cancels each other out as they are both shown to perception blitz characters on the same speed tier as them.
just by what we are shown, Deku would be the faster one esp by the wiki standards
"much higher with Gearshift (His Second Gear blitzed Shigaraki to the point he couldn't perceive what happened) Shigaraki already upscaled above 62.27% SoL and Deku was able to blitz him before he knew what was going on.
"At least Relativistic, likely higher in Pink State (Was so unbelievably fast that Garnet and the other Crystal Gems could not perceive or react to him, and they even appeared in slow-motion to him) this would put Steven massively above 33% C.
the MHA scaling chain is far more substantial as Deku blitzed someone who already upscaled above 62.27% SoL compared to Steven with his speed who had the gems appear in slow-motion and not perceive him, putting him massively above 33% C. The numbers don't lie and Dekus feat is greater than Stevens.
I know Deku’s ap is stronger than 12.71 exatons, the thing is that the shields will still be able to block that value decently since he’s still comparable to pink Steven (albeit overall weaker so it’ll be a struggle). The shields will weaken the force of Deku’s one shot attack and even more if he multi layers his shield (which he can). Also in the same jasper fight he also opted into spamming the shields and killed her with a massive spike shield wall.
His shield and bubble would for sometime but hes still the weaker, slower, and less skilled fighter here putting Steven at a pretty bad disadvantage
Steven has to get past Deku just dancing around him thanks to Analytical Prediction and Danger Sense before even hoping of spamming his shield and massive walls, restraining Deku with it like he did Jasper wouldn't work as Deku LS and AP are far greater meaning he could shatter them and move away in time (if he even caught him to begin with), not even including the fact the Dekus range is FAR greater than Steven's (Hundreds of Kilometers which is exclusive to his bubble and something he doesn't do often VS Thousands of Kilometers which is something Deku can use and was shown to be just a byproduct of a weakened and exhausted Deku)
Smokescreen will completely cut Steven's vision off from seeing Deku meaning he has a pretty damn good opportunity to sneak attack Steven before he can put up his shield or bubble tho he could likely use his "screams" to disperse the smoke
Blackwhip will be as useful as ever as it gives Deku ways to bind or defend against Steven if need be esp given Deku is Class T vs Steven's Class G
We already know about Fa Jin and Gearshift and Float doesn't matter much given Steven has his own Flight he can use.
Deku's intelligence as well means he'll quickly catch on to how Steven fights and use that against him as the more skilled combatant.
He can also just heal himself with his spit if he manages to weaken Deku’s one shot. His spit was potent enough to resurrect someone that has recently died.
Steven has never shown iirc to do this in a combat scenario so it'd be out of character but something he could do ig.
I really don't see much for Steven here, Deku just has all the tools in his kit to pull this off so its pretty obvious i'm voting him.