I have been searching the web for a direct answer to this and decided that this thread gave me enough info to roll the dice.
I just installed 295/60R20 BFGoodrich Mudterrain KM3s on my completely stock NO mod 2021 AT4.
There is a slight rub in the wheel well but nothing a little trimming won’t fix. I do not want to void my 100,000 mile warranty so I’m not going to get any additional lift unless these tires create problems (any info on this would be helpful).
The truck looks pretty bad ass. Huge fan of the AT4.