Justin mostly use Blues to teach lead guitar techniques.
In Grade 4, the 3 modules : major scale maestro, essential blues lead guitar and blues licks.
In Grade 5, major scale maestro 2 and transcribing blues solo.
In Grade 6, blues lead 2 and 3.
Also, the new blues immersion course which will start on June 4. https://www.justinguitar.com/faq/blues-immersion