You are putting 100% reliance on the fact that what is claimed and printed on that psu is reality. As shown in the posted video, and is reality for many psus, what's printed and what's real are quite often 2 different things.
If you ask, and many have, every single person answering will say 1 thing above others. Quality psu. The reason for this is quality psus, no matter the actual wattage, will live upto their claims.
It's quite possible, even probable, that for as hard, 40% on your average, as you have been able to push your cpu having not only a higher wattage gpu and it's consequential ability to raise settings you'll increase cpu usage. Instead of being held back at 40%, you'll be looking at 50% or better average usage.
Basically moving from a 100-150w average usage for the entire pc, to something higher, possibly approaching 150-200w.
With so many units failing at between 50-60% of claimed wattage, you can see the concern.
And no. It's not 100w cpu. The TDP of a cpu is thermal design power. Thing about temps and actual power used is they are different, but usually so close, within 5 watts generally, that the temp was adopted as the same as power output. TDP itself is a number based on actual power used by a cpu during the process of running an intel standard set of applications. It's not the maximum power available for use, but generally considerably more mediocre. For maximum power usage, Peak Power, it's mostly @1.5x-2x TDP. For i7's it's closer to 2x, i3's it's right at 1.5x. So figure maximum power with all 8 threads running at 100% will draw pretty close to 200w at stock voltages.
What that means for you, at 40% cpu usage is your cpu is actually using somewhere around 80w from the start.
If you figure that the gpu is capable of running @60% that's @60w. Add another 50w from the pc in general between ram, drives, motherboard, fans etc. 80w +60w +50w during a good gaming session puts you at @190w usage. If the cpu is pulling 50%, that's @200w usage on a 250w questionable psu that has a maximum of just 204w on the 12v rail.
Simply, it may work well, but the chances of catastrophic failure are way to high to have any recommendation.