I'd say the exact opposite. Band position effects the height of the cylinder relative to the torso.
If the band is too low, the cylinder valve will push forwards of the shoulders. That, obviously, forces the top cylinder down (simultaneously raising the butt) and trashes any hope of good cylinder trim.
If the band is higher than necessary, it drags the valve down the torso from the armpit. That stresses and complicates hose routing and comfort.
As the band gets even higher, it can also reach the balance fulcrum of the tank... and the snap becomes unable to keep the cylinder butt down at all. The cylinder will just pivot.
You can shift tank location to trim yourself in backmount, but sidemount isn't backmount.
Luckily, in any decent sidemount rig you can easily polish your trim using a decent weighting placements. The XDeep spine weight pocket is perfect for this.
Band location has a direct and critical impact on cylinder trim. That location is determined by correctly sizing the harness.... and the simple application of a tape measure.