A nice 8 minute improvement, but Sub-6:30 is definitely doable. I lost 6 minutes on Gladsheim 9 and another minute in Chapter 2.
There's definitely a nightmarish degree of RNG when it comes to this category. First, you need the THT (Treasure Hunter's Trophy) quests to appear as early as possible. For me in this run, though none of the THT quests appeared instantly, they did all appear reasonably quickly. THT4 was especially kind, appearing after 2 quest cancellations instead of ~20 from my previous run, which is why I was able to pull 7 minutes ahead right out of the gate in Chapter 8.
Second, you need Gladsheim floors to generate in your favor as well. You also need to make sure you're checking pretty much every room in Gladsheim too because otherwise you can easily lose minutes in the run. Gladsheim can also have a very nasty tendency of being a troll in how you go about locating the corners. That said, it's always satisfying to see this dungeon blown away in 1 sitting.