Kaworu knows Evangelions armors quite well. I'm not sure if that could be of any use, but if necessary, he is there with that sort of information.

Yes, good option! Equius doesn't know Kaworu died during last battle, but it's probably for the best? unless he manages to get around Kaworu's incredibly vague answers, it's a thing that can happen.

AND. I just saw an Equius post I missed (sob). Kaworu knows French (and a bunch of languages) 8D