I like the eye changes, but the fact that they can only be bred after this event sucks.
OKAY now hear me out I post like... never so sorry if this makes minimal sense
most of the eyes on the adult dragons are so tiny that there's not much of a difference? I mean, yes, there is a difference, but it's incredibly minimal. The colors look good on babies, but once they grow it's harder to tell a lot of the time. Mind you, not multi-gaze or primal, of course.
I actually made a little chart on some dragon species + elements to compare. Sure, it depends both on species + element, I do admit that, but on quite a few breeds it just doesn't seem to do much.

Common and rare mirror eyes are actually different. I had to zoom in to make sure. There's dark pixels in the back of the eye for common, and they're at the front for rare. I can't tell the difference if I'm not zoomed in :(
The eye colors aren't
BAD it's just that they're hard to see on the adults. And these aren't gened, so I'd imagine that it would be even harder to see the changes.