The earliest inverting modern roller coasters only featured corkscrew rolls and vertical loops. Which was the first coaster to feature a different inverting element and when did it open?

The Orient Express Rollercoaster was the first to have an inversion element called a Kamikaze Curve (aka boomerang or batwing). This ride opened on 4 April 1980 and sadly closed on 26 October 2003. The park sited that the coaster was too expensive to maintain and wanting to use the area for a different ride as the reason for closure.

https://www.ultimaterollercoaster.com/coasters/history/timeline.php
https://en.m.wikipedia.org/wiki/Orient_Express_(roller_coaster)
https://coasterpedia.net/wiki/Orient_Express_(Worlds_of_Fun)