2 ppm is a lot of iron. Your lab test from a few years ago showed 1.46 mg/L (ppm), so saying your iron test result out of your iron filter Is less than 2 ppm is not saying much. Maybe you were talking about your raw water.I then tested for Iron. No Iron detected in my sample from the faucet, no Iron detected in my sample from the faucet that was brown from the bromine, no Iron detected in my sample after the Iron filter. I then tested the raw water and detected Iron. My test has a color wheel but I never saw an exact match to the color in my sample and the wheel but I would guess its less then 2ppm iron because after 2 the color wheel was way darker then the sample. Based on this I think my Iron filter is working to stop the Iron. My water softener is also filtering what ever is causing my water to turn brown when in contact with Bromine but it is causing the resin to become exhausted way earlier then the softener is programed for. I am going to need to get the softener regen dialed in to eliminate this issue.
Does my assessment seem logical? If my issue is not Iron then what is it?
If your softener is dealing with a residual of 0.3 ppm, for example, you would want to give your softener some help by adding treatment periodically.
I would expect bromine to turn ferrous iron containing water clear, after the ferric iron settles out to the bottom. Same with chlorine bleach.