Chemically, dolomite lime = CaMgCO3 (calcium magnesium carbonate). Hydrated lime = Ca(OH)2 and is acidic, offers no buffering (buffering up is that carbonate molecule, the CO3, and any time you see that combination, you know it's going to contribute to alkalinity, i.e. resistance to pH shift). I can see that causing problems in coir cultivation.
Other sources of calcium carbonate (CaCO3) include oyster shell (flour) and crab and shrimp shell meals. These meals also offer chitin.
I believe that the prilled products are bound with clay, and I would not be surprised if that clay is adding something unaccounted for in the mix.
I can see any carbonate source being depleted after a grow if using more acidic watering/feeding parameters, because all that's needed to get it into solution is a pH that's in the 6.0 range.