I mean, the video shows a good'old butt-push technique, but it is mostly useless when one doesn't have an excellent feet grip (which typically is pretty rare around the area you just failed to ride through...) to push at 20-30 degrees
anyhow, back to the tip:
So, this plank, if one does fall over often or anticipates to, one can certainly find it worth to carry it around. It can also act as a bench or table, or safe ground to rest the bike on center/side stand overnight, for those camping. Do you have any other unusual purpose for it?
It got me thinking, the board has to be tall enough for lifting purposes, and large enough to avoid tipping sideways. In fact what you could use is 2 poles resting in triangle with the ground. Maybe aluminum is solid enough and lighter; maybe you can also find something telescopic like in aluminum crutches, to reduce length.