If I had access to clean well water I would absolutely use that instead of RO water and CalMag. But with my water access filtration is the only option. And once it is filtered something needs to go in as a buffer to accept most liquid nutrients. I have found that most hydroponic nutrient lines do not have enough calcium in the base nutrients. So adding some in is the only way to get a complete dose in there. Again, this is not just for the sake of the plants but for the effective mixing of the nutrients as well. I personally use separate calcium (Demeter's Destiny) and magnesium (Sweet) products for specific control of what is in my feedings. When growing in soil water days are just that, water and nothing else. Ideally I have built sufficient amounts of both elements within the soil to carry from feeding to feeding.
Clearly all of this makes my way the obviously superior one, and its the only way it should be done (hack, hack, cough, cough,.....chuckles).
But seriously, I have seen your grows and your plants are gorgeous, so clearly what you are doing works. So this is clearly yet one more case of what works for me doesn't necessarily work for you or is inefficient in your system. That is what makes this plant so great, we can all have success with so many different ways of doing it correctly.
