A "must"?... absolutely not..
Have some noticed/claimed more "equal" growth patterns on SPS,etc when using one.... yes
Should a maxijet be run on a wave controller.. NO..
Its designed for continuous operation and should NOT be stopped/started frequently..
Invest in a proper controllable powerhead like a vortech/jebao,etc... if you want one..
But people have been successfully keeping reef tanks for much longer than "wave makers" have been around..