I can't believe people can race to Sag A* in ~8 hours. I really can't.
I've never raced to the core but I believe I'll do it someday just for the "fun" of it. You need to make the distinction between "exploring" and "traveling". Racing to the core requires the strict discipline to NOT explore along the way, don't even bother opening the system map. It's jump, scoop, and after FSD cooldown jump again, period. It also requires very focused ship outfits too, like very small fuel tanks, absolutely no useless mass like shields or sensors, you optimize purely for scoop speed and jump range. Planning ahead of time can shed a lot of minutes or even hours off of the trip too.