Yes. Optical is compromised. But the question is can you hear it? That is equipment dependent… is your equipment sensitive enough to make it obvious?
Only one way to find out. Get an appropriate digital cable.
I have been pursing high end audio for fifty years. I have always known I would continue pursuing better and better systems. So for me, I would always stay away from known potential issues that could compromise the sound… like different length speaker cables. Evaluating sound quality is very time consuming. So I would spend my time on the big stuff… evaluating components, cables, interconnects, power cords and just take for granted stuff like cable elevators, no different length cables, etc.
That has been my strategy and it has worked as each generation system has gotten much better and I now own a world class sounding system customized to my taste.