Do you think a 1/4 ounce lipless crankbait like an Xcalibur XR25 would be too big for white perch and yellow perch?

I seen a yellow perch hit a mepps number #3XD inline spinner. The tremble hook just squeezed in its mouth. It's a 12" perch.

No, I've caught yellow perch on baits almost as big as them. It may cut down on the number of bites but the quality will most likely go up too. 

i have two tiny ratl traps i use for white and yellow perch, cant remember exactly but smaller than 1/4oz. but they will chase bigger baits and hit them. i had a nice yellow perch follow in a t-rigged zoom super fluke i was bass fishing with before, wish he wouldve ate it. it was probably a 2-3lb yellow perch

Some times it's amazing how a small fish can attack a larger lure, and the opposite happens all the time too, small lures catching big fish.  Depending on the type of lure small can be defined by weight or profile.  I use a lure that is about 2" in length with small trebles and weighs 1 oz, I consider it a small lure.  I also use lures that weigh only 1/8 oz but have a profile of 4", my opinion is a medium sized lure, both lures have caught fish from 1# to much much larger.  I guess I define small as profile as opposed to weight.

I caught on the same day and same pond with 1/4 oz rattle trap blue gills and 6# bass.

I've caught perch on jointed Rapalas that are twice as big as the fish. Several.

I had a small crappie guarding his bed eat a magnum yellow magic popper the other day....

I've caught Crappie with 1/2oz spinnerbaits.  One time while swimming a Rage Shellcracker through a tree top a one pound Crappie nailed it. 

 

If the fish are hungry enough they'll eat anything.  With smaller baits, you'll get more but smaller fish.