He will be at a stage where increasing his power output is far more important than developing strength using the squat.
For me personally, leg speed, tendon strength & elasticity are the defining qualities of the fastest 100m sprinters.
Bench, squat, oly’s & deadlifting are ‘usually’ the Western standard that just don’t cut it in each department in developing those qualities to world standard IMO.
Yes they can too an extent but there are far better means.