You need to evaluate YOUR needs. What kind of targets do you shoot at? Is recoil a concern? How good a shot are you?
Shot is expensive so cutting back saves a bit of money. I practice trap shooting using 1 oz loads, but always use 1 1/8 in competition. I cannot afford to miss a bird when it matters. But trap is a different game. I used to shoot 20,000 rounds a year so saving money on practice shells mattered. Cost did NOT matter when competing.
For the vast majority of CAS shotgun targets, 3/4 oz will not have many disadvantages. If you have a stage with aerial targets or stubborn KD's it is not a big deal to carry a box of heavier loads to get the job done. Then go back to the lighter loads.
Pattern YOUR gun with YOUR chokes, and YOUR loads. There are a LOT of perfect scores shot in skeet with less than 7/8 oz of shot.
Having said all that, unless you flinch, or recoil affects recovery for subsequent shots, more shot will always be better.
My CAS load is 7/8 oz of 8's @ 1050 fps I have a box of 1 1/8 8's @ 1145 fps if needed.
Coffin Filler