My trailer towed fine with my half ton up to about 62MPH on the ball, at this point sway started to be an issue depending on other factors like road surface, passing vehicles, downhill grades, etc.
The trailer was to the greatest extent very stable up to to 55, and quite stable to 60.
The tongue weight was not an issue for my somewhat heavily sprung 1/2 ton 4X4. At no point did the lack of WD cause any safety issues.
My concern was sway, because "I can't drive 55", or even 60 for that matter.
In the final leg of my last "on the ball" trip I was going a little faster than I should have been with a big truck to my left, and a big truck on my right, going slightly down grade in a gentle curve.... It got to going pretty good..
(on the I-20 "bypass" south of Dallas)
Found a used "premium" hitch on Ebay the next week. Since then, I don't worry about sway.
A man has got to know his limitations, one of mine is driving 55, cant do it.
If I could have driven this slow, on the ball would have worked fine for me
Brevi tempore!