I struggled, and struggled and made it much harder on myself than it needed to be. .............then got PTSM and did the exercises for the minor penatonic scale (Since you said major, can I assume you know minor ?). Once I had the minor scales down. I just figured out what majors go over the top, and since I knew the root notes for minor, it was easy, when I am in the same area of the fretboard, after a while , it becomes habit since when you go fast, there is no time to think
Example : Box 1 Minor is
5- 8
5-7
5-7
5-7
5-8
5-8
Box 2 minor
8-10
7-10
7-10
7-9
8-10
8-10
Major Penatonic (same fret spacings as Box 2 minor, same starting point box 1 minor)
5-7
4-7
4-7
4-6
5-7
5-7
What made it click for me, as we all seem to learn box 1 A-minor penatonic and rock the snot out of it, learning oh, A-major penatonic has the exact same starting place, and oh, and I can use box 2 shape right there of the Major.
Seems weird at first, but it stopped me over thinking it, and since I was overly comfortable with Box 1 minor, the transition mixing in major was easy, and I didnt have to look for the root notes.
Another neat trick, Say a blues in A, well, box 1 minor penatonic, also has box 4 of the D minor penatonic (which is also the IV chord), same starting point. and E minor penatonic , the V chord is box 3
It was easier for me to learn what boxes fit over each other than learning where everything is, again, of course meaning I knew the 5 shapes to begin with from A minor.................hopefully that makes sense