I find this hard to believe in my case. I do a no sparge with a a HERMS. I add my acid to room temp mash water, and minerals with the grain. Stir with a large whisk and start the recirc.
And I should have included that discussion that moving the liquid with recirculation is much more effective at homogenizing than is moving the solids by mixing, since I brew with RIMS. You caught me there. I do add some additions in the tun since I can reliably count on the recirculation to mix it all up.
Chalk solubility is largely driven by pH and ionic concentration. In most potable water, chalk has a saturation limit of around 50 ppm if I remember correctly. Many groundwater sources can have much higher concentration due to dissolved CO2 in that water that increases the solubility of chalk. This fact is one reason why increasing atmospheric CO2 is killing ocean reefs. The higher percentage of CO2 is making the water more acidic via carbonic acid and that is dissolving the reef exoskeletons.
PS: Unless you are going to the extreme of dissolving chalk with CO2 (as mentioned above), don't use chalk in brewing. It does not dissolve in the mash to the degree desired and any chalk that carries over into the kettle will increase the kettle wort pH and that might not be what you want there.