If your mechanic was not familiar with the Alde system, you should find out exactly what his process was and report back here. The process is not brain surgery difficult, but there is a procedure to be followed. There are only two types of glycol that have been used in the Alde by nuCamp (edit: in the US). The first was Century. Currently, the Rhomar/Alde fluid is the only thing that is recommended by Alde and nuCamp and will satisfy the warranty.
@Mags80 here is a link to the post I created when I moved the spare to the tongue of my 2018 320S (with lots of detail). I was towing with a 4Runner. You should still be towing level, but moving the tire will add more weight to your tongue. The 4Runner suspension was soft so it squatted, so I had Les Schwab Tire add Sumo Springs to help level. I would guess the Highlander suspension is stiffer.
My 320S was a non-boondock, so wheels/tires were 14".
I assume you don't have a foot plate or wheel attached to the jack post when towing/backing up to give more clearance?
I had to back into the driveway at an angle before straightening out to get the 320 into the garage. It was a standard 20' driveway which meant a lot of back and forth to get the trailer into position once I was over the hump. (I was parking on the right side of the garage but backing in from passenger side blind).
Went from a 2017 Tacoma to and 2024 Tundra Hybrid (actually had a 2023 Tundra non-hybrid but it was stolen) Statistically the hybrid is not any better on the highway for fuel mileage. It's actually supposed to be worse due to the weight of the batteries. Toyota doesn't advertise the hybrid as a fuel saving system but extra horsepower to deal with turbo lag and more importantly much more torque. I'm really impressed the the hybrid system. Fuel between the non-hybrid Tundra and hybrid on highway seems to be a wash. The hybrid system doesn't normally kick in unless you're going under 50km/h. However, I have found there are odd times on the highway, down slopes and letting go the acceleration, the system sometimes went into EV mode. If you can I'd almost wait a year for the Tacoma, as this is a new model and they're still working out some bugs. The new Tacoma is so much better than the old in nearly every aspect (IMO). Also note that with the hybrid you'll lose most if not all rear seat under storage. The real fuel gains are within city driving.
We have had a discoloration of the wood near the floor under the refrigerator and microwave in the hatch back of our 320 boondock CS. I have sealed everything from the rear, only to find now the black seal material they used on the electrical outlet on the rear outside panel is a foam material. The outlet was filled with rainwater and leaking into the cabinet behind the refrigerator.