I like the expression idea as well
I had a cat IRL which had unlike it's fellow cat permanently a very big pupil unless the sun was shining big time.
It gave him a littlebit of a melancholic and wise expression.
I loved that about them his eyes were not so much static because the lighting in the eyes plays a big role in making the eyes lively.
I remember Callie asked me one time if I ever noticed why the Kittycats' eyes had that lively outcome after I remarked I noticed that they are.
Frankly I had no idea I only knew that was true.
It turns out the highlights in the cats' eyes are super realistic.
The light comes from the same direction on both eyes and the highlights are on the outside of one eye and the other on the inside.
I have seen breedables who exactly mirrored the highlights along with the eyecolor why the animal looked not only static but a little weird also a bit crossed eyed.
So perhaps even with a larger variety of eyeshapes the Kittycats with these excelent highlight will still look good.
I have to see it to know it though :-)