Using different scales in different positions (CAGED)

If it’s the same scale the pattern will work anywhere on the fretboard. With 6 strings at 24 you should get I think its 3 different spots to play anything for the most part.

I’m gonna be kinda opposed to what may be thought by papa Gates but I don’t know any of the names of the scale positions(C,A,G etc.) I just know the notes that are in the scale and where to find them on the neck and go with that. Applying those works for all the scales. Basically know which notes make up the scale and find them everywhere on the fretboard and you pretty much have your positions figured out (this helps with the modes also)
With A shape scale over the D chord he probably means the A shape D major scale over the D chord. So he’s effectively saying like hey you can find the D major scale here as well. As long as the scales are made up of the right notes you can use whatever scale and play the scale wherever you want.

Again I would urge you to learn the notes that belong to the frets.
Basically you have A Bb B C Db D Eb E F Gb G Ab A this is the open string up to 12th fret on the A string(12th fret is simply an octave of the open string). Now you know that in between each note is 1/2 tone difference(A Bb is a 1/2 step and Bb to B is a 1/2 step etc) you also know that moving one feet up or down is also a 1/2 step(open to first fret is a 1/2 step, first to second fret is a 1/2 step). Know when you are in standard tuning you are tuned EADGBe which basically means that string that’s turned to E starts on the E but the intervals work the same. Now take the C major scale for example(with the notes C D E F G A B ) and find the notes of that scale on all the strings. It doesn’t matter which position you use as long as the notes you are playing are correct. It’s note like you can only use the 2nd position for specific cases you can always use the 2nd position if you want to because it simply has the same notes in it.