Your post was too long to quote.
people will argue against the noticeable gains from any upgrade. Most have an agenda , whether it be because they are afraid to do something, they are a brand lover and feel the truck was made from Nasa scientists and cant be any more properly designed or maybe they just are budget conscious and hate on the people spending a modest amount of money on their ride.
either way you are fairly ill informed , these engines benefit from headers, always have. Ive had headers on multiple LS engines all with big gains. If there wasnt any gains I wouldnt have done it a second or 3rd time. They made an insane amount of header options for LS for a reason.
im not calling you out , but throwing random numbers out their and theories does not equate to real world , if you dont think its worth pursuing thats fine and dandy. But to kinda witch hunt against it is silly, anyone who understands motors understands the purpose and application of exhaust .
To say you lose power down low is also funny, who the heck is looking for power below 2500 rpm? Ive never seen someone concerned about power at such low rpm.
Regardless of your stance the chart shows noticeable and desireable results.
Ive been happy with my previous model year trucks with headers installed, all put a smile on my face and I felt was the best upgrade I made on those vehicles.
Ive had buddies with the same truck drive mine and they all noticed the difference between our trucks.
i dont see how these 2020 with the same motors wont have the same results.