A question about the effective practice of scales:

I've been devoting half an hour a day to scale practice, with four goals: building dexterity, building familiarity with the fretboard, laying the groundwork for improvisation, and being able to claim that I'm keeping up with Doc Watson in at least one respect.

What I'm doing is practicing seven major scales, each in several boxes up the neck, and in several patterns other than the straight scale.

On my keener days, I try to name the notes in my head as I go, in the interests of learning better where the notes are on the fretboard. But on my lazier days, I drop this mental part of the exercise. And I've found that I can play the scales and exercises much better if I'm not thinking about the note names, and even better if I'm thinking about the geometric pattern of the scale and intervals.

(By geometric pattern I mean things like: the major third above a given note is one string up, one fret back, and the octave above a given note is two strings up, two frets up...)

So my question is: what is the most useful thing to be doing with your brain while practicing scales, with the object of learning to improvise? Think about the note names? Think about the spatial patterns? Or not think about it at all?

Thanks, Marion