Well lets science this shit up a bit.
Exhaust coming out of the port is roughly about 1500° to 1600°. At that temperature its moving damn fast, but won't actually have that much density for its volume. The boundary layer that forms at the walls of the tube reduces friction and allows for a faster exhaust flow. As the gas cools it gets denser and you need to maintain laminar flow.
but this crap is exiting out the collectors likely still in the 1000° region. Unless they really pinch that tube its not likely going to make much difference.
Course, thanks to this video when I yank my headers off to have them coated I'll likely mark and dimple all of the spots where the spark plug boots are tight. The #7 plug wire actually touches the primary. But thankfully is insulated so prevents it from affecting the wire itself.