I totally understand wanting to keep an older, reliable vehicle, especially a rare RAV4 V6 tow package. Given sky-high prices of tow-ready vehicles, I would make some sacrifices, too.
Scamp is typically lighter than
Casita for comparable 16’ers. Avoid 2021+ as they’ve gained weight since the redesign. Go with a single LP tank to reduce tongue weight. Choose lightweight bedding and kitchenware. Stow tools in a compartment near the center of the trailer. Put your bicycles on top of the vehicle, and stow the ice chest and inflatable kayaks in the trailer (on the floor over the axle). Move them to the tow vehicle when you unhitch.
With some finessing you should be able to make it work with gross weight around 2600-2700# and tongue weight at or below 300#. Check your final axle-by-axle weights at a certified scale and weigh the tongue on your first outing to make sure you’re within chassis ratings and have sufficient tongue weight (around 12%) for stable, sway-free towing. Hook up trailer
brakes and install a sway bar for added safety. Agree that WDH is not the solution here.