Caps, you can't always cover a tech chase option with side b. Ganon just isn't fast enough. Sometimes all you can do to cover di away and tech away is either down b or sh perfect waveland jab/tilt/grab.
Another thing (unrelated): wavedash oos is underutilized imo. It isn't always that great of an option, but Marths who space fsmash on shield have to stop getting away with it unpunished. Even vs ganon. I experimented with it yesterday and you can wd jab, grab, or tilt (on shield) to apply pressure. Just one example of its use. I figured out some more cool **** with it yesterday also and there are a few more useful applications. If anyone's interested, I can go into more detail.