Hack squats can be a great choice for lower body gains and to increase your upper-body mobility.
Learn how to program these effectively by checking out this video below:
Hack squat biomechanics
The hack squat can be useful in driving air anteriorly, particularly at the manubrial level. Humeral extension creates anterior rotation of the clavicle, which pulls up on the upper ribs.
Because there is more of an anterior expansion bias, you will not have as much verticality in this squat compared to others.
The further you bring the bar, the more vertical you will get.