With regard to witness expenses, I and all of us at committee have seen that sometimes an organization will send two witnesses when it doesn't really have to send two. Wherever possible, one witness from an organization usually is enough expense for the committee to pay. If we sometimes need two, at the discretion of the chair, that would be fine, but whenever possible, I think one witness per organization is generally enough if we're paying expenses for them. If they're paying their own expenses, they can bring as many as they want.
On June 23rd, 2011. See this statement in context.