That is less than half of your rated 3 pt hitch capacity. And it's probably fairly close to the back of your 3 pt, as compared to say a 3 pt brush hog that sticks out 8-10' off the hitch arms.
The reason your butt is "puckering" is because that's not enough counter balance weight for a "max lift" on your specific tractor. Your 3 pt is rated for 2310 lbs. If you're going to max out your FEL lift, for one that is a big lift you need to prepare for, you need 2000 pounds on the back to max out your rear
ballast and have true "balance" during that lift.
That rear blade is probably fine most of the time, for any number of random FEL lifts. But when you go for a "max" lift, you need to set up your lift in advance with a max rear weight, not half the rear weight. And yes, that's even with filled rear tires (filled rear tires is a good thing too, but doesn't do as good a job of counterweight, as the rear tires are much closer to the lifting fulcrum, which is the front axle). If you try that, you will see a profound difference in what your "butt" does while you lift it.
This points to exactly what I'm talking about. It is up to the operator to determine these things. Owner's manuals and legal disclaimers can only go so far (remember, they're busy warning you not to drink the contents of the battery). The Korean brands you are disparaging as using "advertising draw"s and "exceeding safety limits" as some kind of stunt, are taking it for granted that the seat operator takes all these things into account before they start performing operations like "max lifts", etc.