Many with Left side tighter than right?

I would not prioritize tight muscle work of any kind,as that is the effect,not the cause.Address the cause first,either bilaterally or monolaterally depending on the means you use,and monitor how this affects the problem you are aiming to solve. I am not familiar neither with foam roaller,nor with any specific " therapy " mean,but I would surely stay away from the bosu,as it most likely would worsen the problem,and possibly allow for more to come.

Paradoxically enough I would also stay away from most proximal (core) work,and concentrate on balancing out distal feedback to the brain from the limbs at least until less and less compensatory patterns (tightness) are evident.