Hi!
To set up Keylab knobs with logic you have to set it to relative and find the correct Multiply setting in the Controller Assignments Learn Mode window. Also go to Logic>Preferences>Control Surfaces>Setup>(choose Keylab)>(change the "relative change mode" to "Fine"). These two things allow to you configure the knobs to relative control - also for some knobs you might use the "-" (minus) modifier to set the Multiply setting in the Learn mode window.
I finally got it working!

You can too by tweaking these settings:)