There should be little reason to exceed 150 ppm in practice. Since calcium is paired with a variety of anions, boosting the calcium means that the water would also have high concentrations of some or all anions its associated with. That could be a formula for minerally beer flavor.
Considering that calcium complexes with phosphates in the mash and precipitates out, it may be undesirable to overdose the mash with calcium. But considering that I know of brewers that have overdosed with calcium-containing minerals, it does not appear that the precipitation reaction is excessive or detrimental to the resulting beer. So there isn't an upper limit for that reason.
At 133 ppm Ca, there is no problem.