I agree, it does become a hard with Will and Kat (including the MC even) looking the same.
Unless a new character's added to remedy it, but I then it'd just take away from Kat.
And yes, SadCat. Please don't let whatever we're yapping deter you or anything.
However, me personally. I don't think you'd need a full visual difference to achieve the IR effect.
I mean for me, if Kat in a hypothetical future scenario were to roleplay using for example an outfit/or in a certain setting and appropriate dialogue (dialogue will be what carries it) to match, then I'd say it's more than enough. (plus I read smut, so I can easily get over the visual aid (and yes I know, a totally hard flex))
Entirely because this isn't IRL at all, so it can work. Hell that was the basis of my view for the first post I made about it (not IRL porn). So long as Kat's able to feed into it correctly, it'll work (or more like it'll be enough, as a BLEACHED fan, I already knew the road was a rocky one, especially knowing the slim chances of seeing it in a porn game. We'll take what we can get).
Apart from that, I'll just wait till the next update to see how it's handled.