I use a Slow n Sear and the BBQ dragon to get super hot temps. Forgetting the BBQ Dragon for a minute, the Slow n Sear or really any other method that raises the charcoal closer to the grate raises the temp at the cooking level. Some use a Slow n Sear, others use different methods or contraptions like the vortex or hovergrill or even a couple of fire bricks to raise the level of banked of coals.
Also, are you closing the lid when you're cooking? Coming from a gas grill to charcoal this may be your first instinct. The Kettle fire gets hottest with the lid off, unlike a gasser.
I agree with others who've said to let the meat rise to room temp (or to a certain internal temp if reverse searing or the like) before putting it on the direct side of the grill. That will help a lot.
Finally if one were to gauge temps of fuel source it would go something like this: KBB (HOT) - RO Briquettes (HOT) - KBB Comp (HOTTER) - RO Lump (HOTTEST) - Straight Hardwood chunks or minilogs (SUPER DUPER HOTTEST). So maybe try Lump for hotter temps?
Using Lump with a SnS and BBQ Dragon makes me fearful I'm gonna damage my lil old kettle.