The trouble is that it can partially dissolve and then bind together if a large quantity is ingested at any one point. However, if you mixed it into the soil/substrate, it would not be a problem and would cause incidental calcium consumption and that would be a positive thing. You just would not want any extreme concentration "hot spots".
It all depends on how you apply it if you apply it. At the microscopic level, small acid reactions by microbes may allow it to end up fortifying the soil for plant uptake, too.
If I had a bag doing nothing, I would mix it into the dirt. If I did not have a bag, I would not buy one.