Keep in mind that the more complex your design and the more falling water involved in the design, the harder it will be to maintain and keep your waterfall area clean over the long term. This tells us to run the pool waterfall at our discretion.
The more often and longer the waterfall is on, the more problems you will have in the future. The length of time it is on affects the life of the pool as well as the cost of pool maintenance. You can include all sorts of features and functions in your pool waterfall. The only real limitations are your budget and your ability to install your pool.