Joe-

If the plywood is really only 1/4" then it's not much of a shear wall.

If you only make small holes ( 3") & just a few I wouldn't worry
about it.

If you need to cut out a large section just makes the cuts about 3/4"
from the framing so you can put in some 2x4 blocking around the cut.
Replace the cut out ply by nailing to the new blocking. Make it easy
on yourself & rip the blocking down a litttle so the fit up is easier.

Cheers
Bob