Not normally, no, I don’t either. But I hear prisoners have to make a visitor list of potential visitors or similar. Suppose each one was asked that question and each named the other as a “potential visitor”. Wouldn’t one expect the prison to do the same kind of accommodation to that as it would to a normal prisoner with a visitor (i.e., they take the prisoner to a visiting area. In this case it would be the other’s cell. Just a thought.
You should always let accused co-conspirators visit with each other with a recorder going to see if they’ll say anything that can be used against them.