My 400 lb. dieffenbachia is chained up my wall , can I switch the chains to large iron rings with attached stakes so it no longer needs the support of the wall?
You can do that, though if were my plant I think I would cut it back. If you make your Dieffenbachia plant quite a bit shorter, it will send out lots of new growth. The new growth will make the Dieffenbachia bushier and less top heavy so it won’t have to have supports to keep it upright. You can plant the section of the plant you cut off right into the same pot as the original dieffenbachia plant or start a whole new plant.