I have very soft water and after reading stuff numerous times, I've come to the conclusion that for me it's just about increasing calcium and then balancing the sulphate and chloride in different styles. For you it's maybe about reducing carbonates and then balancing sulphates and chloride. If you select different beer styles within the water calculator, does it change the CRS quantity? What doers it do to Epsom/gypsum (sulphates) and to chloride for each style? It tells me to add gypsum/Epsom to pale styles, chloride to dark styles, and some of both to medium styles.
I also think this is a matter of personal taste, as much as about correct chemistry. Chlorides accentuate malt/sweetness, sulphates accentuate hops/bitterness. So the sulphate/chloride balance is a matter of personal taste, I think.
The other issue is mash pH, which I have never measured or worried about. Again, I have read stuff that says that the mash pH naturally gravitates into the right kind of area, in most beers at least. I do leave roiasted malts out of the mash, either altogether or for the first 30 mins or until the sparge, as I believe these can affect the pH significantly. But I will check pH at some point, out of interest, in different styles, to find out what is going on.
I'm not an expert, this is just my limited knowledge and experience. In a nutshell, if I had your water I would focus on carbonate reduction, and experiment with the sulphate/chloride balance in different beer styles, if I were you. And see what the pH is when you mash different styles, to see if this throws up any issues. But I'm aware that, as I did, you will get lots of different advice and it becomes confusing and difficult to know what to do.