Petrucci’s Rock Discipline turned my teen years into a love affair with the metronome where I’d practice chromatics for fucking hours trying to get faster, alas, I never play straight chromatics in any solo I’ve ever written or played. In that regard, Vai’s 10-hour workout exercises that teach you how to start on different notes within a 4-note chromatic can be great practice with one because it makes you mix your starting fingers up so everything isn’t 1-2-3-4, but 3-1-2-4 or 1-2-4-3, etc.
The best practice I got with it was ‘dancing’ on the click, basically improv jamming to it with the intent of burying the shit out of it.