A larger tappet wheel does enlarge the "area under the curve", but also distorts the tappet motion slightly by changing speed on both sides of the lobe.
.050" difference probably has minimal effect; a much larger roller may need more spring tension.

Harley-Davidson has used .855" rollers 1929-83 on all engines, and minimized the side thrust vector by offsetting the tappet center line advanced (earlier) w/r/t the base circle CL. This places the roller over the rising lobe (rather than along side it).
It has been suggested that the optimum amount of offset is ½ the lobe height. H-D 4-cam motors (1929-* 750, 900, 1000, 1200 & 1300cc) with lobes between .220” and .440” all used ⅛” offset, single-cam big twins (1936-83 1000, 1200 & 1340cc) are 3∕32”.