if you send a fast faller onto a side platform you can position yourself under the spot where they land (or as close as possible) and then anticipate the tech in place. if they choose any other option, you can react to it and hit them with something in time.
if you force them to tech on a platform and youre already very well positioned, you can cover all the options: covering tech in place/no tech with shine, then wavelanding onto the platform. if they hit a tech roll, you can cover it on reaction.
if you are in that awkward scenario where you send a fast faller to a platform so fast that by the time you get to them they can do a gettup attack, then youre probably better off not engaging that at all and just waiting it out and reacting or by positioning yourself such that they are forced to do something risky. i haven't optimized my combo game enough yet though; maybe theres a way to avoid this altogether but im not sure. i mean sometimes you can shield to cover gettup attack, and react to all the other options with aerials.