I actually tried it without the support adapters when I first started out, as they didn't seem to do anything when mounting racquetball racquets. But after some comments from others, I try to use them when I can.
Gamma Tech said in a previous reply that ..
Use the largest (i.e. tallest) spacer (i.e. load spreader) available that doesn't touch the grommets or block the grommet holes. It spreads the load vertically and also prevents the racquet from accidentally popping off the mount.
Since your video was showing people how to string using the X-2, it might be good to include the support adapters being installed.
Anyways, to each his own and how they want to string to get the best results possible.