Toyota and Lexus DO tune their 4.7L V8 (2UZ-FE) differently.
The moral of the story is that they are mechanically identical engines but the Lexus versions get 2-3 more peak hp (5400 rpm) and 17-18 more lbs-ft (3400 rpm) than the equivalent Toyota at the expense of asking for 91 versus 87.
Do I run 91 in my GX470? Hell no. Not unless I’m towing.
is it going to hurt my engine? Nope.