Entirely my opinion FWIW, but unnecessary on a .500 for 2 reasons:

- such rifles are not used for long-range precision shooting, so fine trigger control is redundant;

- the weight (hence inertia) of the rifle pretty-much negates any tendency for the sights to mis-align due to trigger-pull weight.

One might even regard any tendency towards a "hair trigger" on a powerful rifle to be potentially dangerous.

Having said that, there is no reason to tolerate an unnecessarily heavy trigger on any hunting rifle, regardless of calibre.