The power of direction, unless provided otherwise in the land trust agreement, is conferred upon the holders thereof for the use and benefit of all of the holders of the beneficial interest in the land trust. In exercising the power of direction, the holders are presumed to act in a fiduciary capacity for the benefit of all holders of the beneficial interest in the trust, unless otherwise provided in the land trust agreement. The beneficial interest shall be indefeasible and the power of direction shall not be so exercised to alter, amend, revoke, terminate, defeat, or otherwise affect or change the enjoyment of any beneficial interest.