This is for Super Trucker and SAint: Though I never wore a SOB while spending almost 3 decades in le, I can speak as a back expert. I have had 4 surgeries and I'm fused from t12 to s1, hence my retirement. Carrying anything over/near the spine will eventually have an effect per my spine surgeon. Those leos that carry one double handcuff case fall into that catagory. Even carrying a notebook in the back pocket is deleterious per the doc. I carried 2 cases and tried to keep them even, but they do move and still dig into the back.
Thought it may not happen right away (and it didn't with me), over a period of years of constant pressure, I believe it is a safe bet the spine may be damaged. You have to decide if it is worth the risk. I would advise since you are just beginning your le career to try to eliminate what risk factors you have control over, because there are a hell of a lot you don't have control of.
Good luck in whatever you choose and Good luck in your career. Stay safe and VEST UP!