For the 16+ models the LC is stated as 8100 lbs of tow capacity and the LX at an unexplainable 7000 lbs, unless the info I looked at is wrong all together.I suspect Toyota voluntarily derates because of added equipment which increases vehicle weight. They probably did the SAE test with an LC and rather than re-run the test with the LX they simply subtract the impact of the added weight, since TW must be 10%. They likely figured few LX owners will tow so it’s not worth repeating the test.
If you want to read the ins and outs of J2807, have fun:
How is that a test with a LC and then applying it to a LX?
Maybe I misunderstand the point you are trying to make.