I'm not denying that there's heat underhood. Just that engine bay covers are not in any way adding or trapping more heat from the engine. While benefitting radiator efficiency as mentioned earlier.
Chopping the covers would be interesting. Yeah, it may make better clearance for the...
I wouldn't be so quick to remove the engine covers. The "engine bay heat" discussion is a red herring IMO. Besides, Lexus validated it so it's not causing any "more" heat to be of concern to negatively impact anything.
What is important is that the LX engine covers are a part of the airflow...