Recently, one of our customers (a manufacturer of machinery for paper cups) required a superbend from us. It had extremely tight tolerances and needed to be tough enough to handle a nuclear explosion. I exaggerate a little, it needed to survive parcel and multiple LTL shipments.
The center to center offset was to be 13.78″ +- 0.015 in tolerance.
The wye had only a 10° angle to divert a large cup moving like a bullet to either side of the wye without as much as a bump that could damage the cup.
The bottom line here is simple, but not glamorous. Making this wye was a tedious process. But, it has changed the ways that we have made wyes for decades. Now, we make superwyes.