Figured he would do that, which is just fine, but I bet if he invested in a bender to do 3" he would pick up alot of new bussiness… it seems once a month people on here alone are looking for 3" work, and pie cutting and msc bend cuts and 11ty time the welding gets old.
Also I know the physics behing it too, and have seen the tests also the old crush VS mandrel, but when it comes to tight bends or bends past 90 deg, a crush cuts down the inside dia ALOT and will effect flow when there are many bends like that. but yeah a few small dia crush bends aint no thing.
It also come down to fit and finish, even if people to make it a habit of looking under your ride to check out the exhaust… I wouldnt want some nasty ribbed condom looking exhaust tubes under my car. Peace of mind alone.