Route of Oppressive Power isn’t an OW route, just a route with a wide short bit that takes big gear. No hand stacks or OW trickery necessary. Mostly hands.
Creation Of The World is THE OW test piece of the dacks. Originally 5.10, but feels more like 11+. No face holds, just pure OW madness
Emily Doesn’t Have a Clue, 5.8, at Lost T offers some opportunity to practice offwidth technique through a couple roofs if you ignore the face holds. There is everything from fists to tight chicken wing/ arm bar and a couple decent calf to knee locks.
The first half of In the Rough at Chapel Pond is a flaring off-width. Not sure if it's what you are looking for though as the flaring aspect may require different techniques.