Add a 2x4 nailer below the panel from stud to stud and contacting the sheathing. Staple in to the nailer.Why run the wires into the side at all? Just bring them in the bottom where it's all easy to get to
This...I hate the old style staples...use the plastic straps with nails or stackers.
That makes a lot of sense!!!I also try to avoid cable entries in front of neutral and grd bars.
