The author kinda nailed the sweet spot--thus far, anyway--in Ruri being super extra on the flailing apologetic introvert mess, but keeping it just this side of endearing and cute and not annoying or tedious.
I think it's the live commentary from the Stream Chat that helps "straight man" her behavior, actually. A good choice; allows her to breathe a bit and cut through the in-person dialogue with "reactions" that pace it out a bit better.