After 1 seconds, the kinetic energy will be .5 m v^2, i.e. .5J, but you'll have expended 1J to power it. So far so good.
After 10 seconds, the kinetic energy will be .5 m v^2, i.e. 50J, but you'll have expended only 10J to power it. that's odd.
After 100 seconds, then k.e. will be 5000J, after expending only 100J to power it. That's bad.
Note how energy is "consumed", but it still gains more k.e. than is spent powering it. That's free energy right there. If you can close the loop and bleed off some of the free energy to power it, e.g. by attaching it to a wheel and getting it to spin a generator, then it will spew out energy from nothing.
That does not make any sense. Why do you think it does make sense?
Note how energy is "consumed", but it still gains more k.e. than is spent powering it.
No it does not. It gains exactly the amount of kinetic energy equivalent of what ever is powering it. What has that to do with reaction less or not? Nothing obviously. And when we talk about reactionless: it gets a little tiny fraction of the energy what is powering it as kinetic energy. If we would use fuel, half the energy would go into the fuel and the other half into the craft.