I've created a dynamic pool and even though I have Allow users to reset / restart their desktop set to NO for the pool the power options still show
Can you make sure that the configuration was saved? Click on edit pool and navigate to the "Allow users to restart / reset their machines" and check whether the value there is "No".
Please confirm if you are checking the power option from the client end or from the Admin end? If "Allow users to restart / reset their machines" is set to YES/NO on the pool from broker Admin UI, the power option will be ENABLED/Disabled for the launched desktop in the Horizon client.
"Allow users to restart / reset their machines" applies only from client side.