No Gojo used the blue which already existed in the sky to drag himself. unfortunately we don't have specific amp for Gojos speed. Sukuna with or without blue he was keeping up with Gojo. I'm talking about when Sukuna and Gojo were
in health. So I don't see him getting too big of an amp.
Sukuna wasn't serious at first domain battle+that was kind came as surprise. Also idk man looks like its more of an teleportation than speed. But i will leave that to you as later onwards in chapter 231 and 232 Despite Gojo was chasing Sukuna. Sukuna without DA was keeping up with Gojo who was using Blue. So i think amp isn't that big
Yeah but Purple is currently void hax so idk. Yami doens't have Resistance for that.