Load range E tires have more side wall plies than say load range C tires. Part of it is due to the fact that a load range E tire is meant to handle more weight and therefore has higher air pressure.
For myself, in order to reserve the truck I just had to put a $1,000 dollar deposit down. That along with a verbal agreement was all that I needed. Later on I did go back and get a purchase and sale agreement, just because with the looming tariffs I was nervous and really wanted to lock it down...
Here is a later article from Reuters that mentions what Toyota might do.
https://www.reuters.com/business/autos-transportation/pre-tariff-cars-us-dealer-lots-buffer-against-price-hikes-2025-04-02/
So if I understand you correctly, you want KO3s that fit a 18" wheel to be offered in two load ratings. Load C for people that mostly use there vehicles on the street, and load E for those that do a lot of off road driving. Do I have that right?
Toyota will not increase the price of there cars despite the tariffs. :)
https://www.reuters.com/business/autos-transportation/toyota-says-it-will-maintain-operations-despite-us-tariffs-2025-03-31/
How to use the Aux switches can be found starting on page 481 of the owners manual.
https://assets.sia.toyota.com/publications/en/om-s/OM35B86U/pdf/OM35B86U.pdf
The 4Runner hybrid has 2 plugs in the engine compartment and 1 under the dash. There is one more but I'm not sure where it is yet. You half to purchase the pigtails separately from Toyota.
I also talked with my dealer yesterday. I have a deposit down on a Trailhunter that is supposed to arrive between 5/3 and 5/21. I was told that as long as it actually arrives between the given dates that they would honor the agreed upon price. So there's hope!