From my point of view, the most important part of an ICP analysis is to first focus on the major elements. The more stable these are within their target range, the better a reef aquarium will run. This is always directly related to salinity: the higher the salinity, the higher the values should be in proportion – and vice versa. In this context, I also consider an ATO (automatic top-off system using RO water) to be very important to keep salinity stable.
That would be my first priority, possibly complemented by iodine – in my tank, one drop per week is sufficient. Once these parameters are stable and within range, the trace elements start to become truly relevant.
Regular water changes with Tropic Marin salt also continuously replenish trace elements. Whether or not to use AFR depends, in my opinion, on the actual consumption of alkalinity and calcium. I personally like AFR because it works very well in my system and adds both major and minor elements in a consumption-based manner.