I haven't used or bought a .750 diameter roller wheel lifter solid roller lifter in a lot of years; most are .820"+ now
I have several older Starrett dial indicators and some cheaper imports, the imports don't read or follow the lifters as well as the Starrett's due
When you think of the contact patch on a .750 wheel versus a .820 wheel on the lobes the difference can't be very much My point is the hang time going over the nose at max lift and then descending on the downhill side can't be very bunch

The difference is small, but
1. The larger roller is in a different place on the lobe at the same crank degrees, because it doesn't contact the lobe at its highest point (like all flat tappets), but at its closest point (tangency); think of it as a clock position
2. At several points of rotation, the larger roller's speed is higher, but not linear or proportionate
3. A concave flank will not like a larger roller at all, and may skip over the root of the reverse curve, then get lofted by the far side. A smaller (than the designed config) roller will simply act differently without damage

A strong enough spring (and/or low enough RPM range) may keep the bits in contact, but a SpinTron will show chatter at (perhaps) more than one point in the RPM range. If the engine must be run in that range severe damage may result.