Recommendation towing capacity advice 3500 lbs

you won't be able to tow this because the actual loaded hitch weight is over your van's max.
the 18RBT has a "dry" hitch weight of 336lbs. the max of the minivan is 350lbs. that "dry" weight rating doesn't include the 40lbs. of the battery, the 20lbs. of propane in the single tank and water and cargo.
just adding the battery and propane weight, puts the trailer's hitch weight at nearly 400lbs.(50lbs. over the max of 350lbs.) and that's before you add water and any cargo in the trailer.

the only one that will have a loaded hitch weight under the max of your minivan, is the one canvas end 13FKT.

second issue is what all trailer in the 3500lbs. GVWR class have, POOR cargo carrying capacity.
with a CCC of only 804lbs., this have to account for the battery, propane, water, options and cargo.

a quote from KZ's website:
"UNLOADED VEHICLE WEIGHT (UVW) - The typical weight of this trailer as built at the factory. The UVW does not include cargo, LP gas, fresh water, options or dealer-installed accessories."
these so-called options are the awning, microwave, a/c, oven, spare tire and a few other things. the weights of these come out of the CCC of 804lbs, along with the battery, propane and water also coming out of that.

when it's all said and done, you're likely to only have 200-300lbs. left over for cargo.

you'll be restricted to only the smallest of hybrids with a minivan.

I tried towing a tent trailer that was 2100 lbs with a mini-van and friends who towed a small hybrid with a Honda Odyssey. Neither worked very well. We both ended up with trucks as we camp alot. (and after the trucks came bigger hybrids :)) After talking to alot of campers over the years and a few transmission guys, mini-vans are not made to tow. if you do be very careful.

Start looking at Popups. Most minivan tow specs also have frontal area restrictions which will rule out TT's, and Hybrid's.

It's possible. But you will be towing right up to your capacity and perhaps over if you don't weigh the loaded trailer and van. You may not want to tow in mountains or long trips though. Another issue is frontal area. When we towed a small hybrid with a minivan, it was only 7ft wide. Yours a 1/2 foot wider. That can add a lot of stress to the tow vehicle. There should be a frontal area square foot rating for your van.

Over the years I have twice towed very close to my rated capacities. Both times I knew what I was getting into and what the limitations would be. The first was like yours, a 3500# GVWR hybrid with a mini-van (summer of '03). The second time was with our X20E (4750# GVWR) and a Chevy Trailblazer (summer of '13). I would describe both experiences as adequate at best. Both times I knew that towing in mountains would be out of the question. However I was setup properly and never felt unsafe or had "white knuckle experiences". In the case of the mini-van we replaced it after the first season for 2 reasons, we really hated owning a mini-van, and we wanted to tow on long trips, and in mountains. We just sold the Trailblazer because it had 160k on it and I really didn't want to spend any money on it anymore. In both cases, prior to towing close to capacity we towed trailers with those same vehicles that were well within capacities and with plenty of spare capacity. Our new to us Sierra in my sig doesn't even sweat towing the X20E.

That said, there is a definite difference between towing up to your limit and having spare capacity.

We had an option on our old Kiwi 17a for an oven, we chose the microwave instead. Our X20E was bought off the lot and came with an oven. We use it for cookware storage.