The only thing the eye piece does is focus your eye to the crosshairs. A by product of this maybe some enlargement of the sight picture but it's going to be extremely marginal that it would reveal more depth of field to any useable degree. But your eye should be focused to the hairs or else with an ft scope your rangefinding may change from its previous setting.
BFTA/NSRA County Coach
CSFTA Chairman/BFTA Rep