Oldschoolskier, this is not about semantics or terminology. Your calculations and assumptions are basically flawed.
You argued that we need to use math to prove you wrong so here it is:
In a normal turn on hard flat surface the ski the ski bends about 2 cm. Lets assume that the ski is pretty stiff and has no rocker, then it would take perhaps 200N max force to bend the ski.
If we assume that the ski "spring" has not reached its elastic limit the energy stored in the ski will be:
E=0.02 * 200 /2=2 Nm.
That is pretty far from your calculation of 980 Nm.
Just for fun lets calculate how much 2 Nm can launch a 100 kg person.
mgh=2 => h=2mm
So, in a typical turn the energy stored in the ski can launch a person about 2 mm, or 0.08 inches if you prefer imperial. Not much of a rebound to collect there.
In uneven terrain like bumps the energy can be a lot more than that, but that was not the discussion point here.
Lets compare that to the real physics behind rebound, converting Kinetic energy to potential energy.
If you are going e.g. 36 km/h the Kinetic energy is
E=mv^2 / 2=5000 Nm
Repeating the above calculation we get that this energy, if it is completely converted to potential energy, can launch a skier about 5 meters in the air.
It should be clear that this is the major energy that causes rebound, and that it is something that need to be controlled.
This is similar to the speed and height a pole vaulter can run/increase CoM height . Same basic physics.