I’m running 38t capacity with a medium cage rated at 33t capacity. Because it is medium, I can go small-small and get a slight chain-to-chain rub without chain sag on the stand. I say on the stand because I have never come close to running a small-small in real life.
You’re smart enough to understand the situation. Just ride it.
I won’t go as far as agreeing that your SS 105 is crisper than a GS Dura Ace or even an XTR RD.
John