What's up with that?

Source: Polestar 3 Upgrades | Polestar US and Polestar 3 Upgrades | Polestar UK

Euro trailers are designed differently with the axles more centered and tongue weights lower. The consequence of this is a lower maximum tow speed than the US, which is generally pretty strictly followed. US trailers have the axles further towards the rear and as a consequence have larger tongue weights, however if you have a vehicle sufficient to handle this increased tongue weight you gain stability at higher speeds.

 

What you are saying seems sound...except that the Volvo EX90 still has 5,000# rating in US.

 

The trailer I plan to tow is 3,300-3,400 fully loaded....so this isn't a deal breaker for me....but it seems disingenuous. Another question is how a find a 2 5/16 trailer ball (the SUV will some with 2")?