Headers & 90 degree oil filter

Your premise about a blowtorch and heat is not correct. Your reason they were designed is DEFINITELY not correct. I always enjoy extreme fear style statements that aren't based on fact. Do you have any clear testing that shows this "blowtorch" effect?

Maybe take a thermometer and see just how blowtorch hot the header is that far away from the exhaust port. Wouldn't as hot as a blowtorch require the header to be cherry red hot? Most of my torches don't work well at most anything that far from the port.

Mountains out of mole hills comes to mind.

Your car, do what you like. I'll pass on those POS 90* adapters every chance I get.

Have a great day.