There are certain sorts of jokes which have only to do with the substitution of the unexpected word in a familiar context. If you translated something into French and then had it translated back into English by somebody who didn't know the original, you'd lose what was funny.
One of the attractions of translating 'Heroes' is that it's not the kind of play that I write. If it had been, I probably wouldn't have wanted to translate it. There are no one-liners. It's much more a truthful comedy than a play of dazzling wit.
You should not translate for more than two hours at a time. After that, you lose your edge, the language becomes clumsy, rigid.