Originally Posted by
Andrew R Stewart
......And if the rim has after pinning brake track machining the seam will nearly disappear as a braking disruption/grab. Andy
To add---
Even if it isn't machined, any misalignment at the joint will rapidly be worn smooth by the brake shoes, and undetectable soon enough.
The move to welded and machined rims was always more about marketing one-upmanship than function.