[ThePair]

A 4Runner has a better tow capacity than a Sienna, and I used that for 10 years to tow a 2720 SL. No problems for me, finally traded it in on a different TV, but not because of the towing, because I didn't want a minivan anymore!

Remember, a WDH is a lot of extra weight, 80-100# all told, and much of that's got to be added to the hitch. Yes, it can redistribute more than than off to the TM axle and the TV axle, which is why people use them, but it's still something. My current TV won't take a WDH either, but my allowances are higher (7700/770), so I'm not worried.

I think your hitch weight isn't quite as high as you think. For a TM it's usually 15% of the total. I would for sure try the CAT scales as outlined above, unhitch everything and just have the TM for weighing. That will be most accurate.

Let us know!