In the Wisconsin code book it's called "erosion corrosion".
The flow and sizing tables are assuming pipe is deburred. Flow rates have s standard otherwise how could you establish a formula.
The ridge itself causes a interruption in flow pressure and violates state code. The result is turbulence and "erosion corrosion".
About 15 years ago I cut out a 2" copper 90 that was spraying from a pin hole. After repairing the leak I looked inside the elbow and it was crazy. It looked like claw marks in the elbow, water had actually chewed through it.
I was puzzled by this so I decided to do a water calculation on just that line which was serving a bunch of fixtures in a clinic.
It was undersized. This compounded the situation and made it worse.
I looked at the other fittings and they seemed fine from the outside. We made a recommendation that it should all be tore out and reinstalled correctly. They did nothing.
About 2 years later we had to go back and replace all of it, pinholes everywhere!
This was the result of two problems.
1.) Undersized water distribution
2.) No reaming whatsoever throughout the system.
Always ream! Formulas used to calculate proper size need inside diameters to remain consistent for the it to work as intended. By not reaming the ridge left by the cutter wheel the inside diameter is reduced, and it is this reduction that causes erosion of the soft copper.