The last time that I added calcium hydroxide I was trying to match "Black Full" profile in Bru'nWater for a Russian Imperial Stout:
* starting with soft water with 3 ppm sulfate and 4 ppm chloride and 5 ppm calcium
* campden to neutralize chloramine -> 20 ppm sulfate
* added enough Epsom salt to get 5 ppm magnesium -> 20 ppm sulfate
That was as much sulfate as I wanted (total of 44 ppm), but Calcium was still only 5 ppm
* Calcium chloride to bring chloride to 42 ppm, which only brings calcium to 27 ppm
I still need ~25 ppm calcium
* Pickling lime to bring calcium to 55 ppm
Because this was a very dark beer with a lot of roasted grains I didn't need to add any acid to counter the pickling lime. I got pH=5.45 with no acid addition.
And that's the one and only use for calcium hydroxide in brewing: to add alkalinity when using roasted grains. Hydroxide is a very powerful base. The calcium is just along for the ride.
There was no need to add epsom salt to that RIS. I promise that you couldn't taste that 5ppm of magnesium. And you would not have noticed the additional chloride or sulfate from adding more CaCl2 or gypsum.
It would have been better to add more CaCl2 to bring up the calcium (and chloride), and then add alkalinity with baking soda. Then you'd get the added benefit of the sodium ion, which adds a nice touch to stouts.