The irony with your comment is that this is exactly one of the purposes of Test Pilot - to give new features a trial run rather than just "cramming stuff in as default".
It's an opt-in experiment, and at the end it's possible to a) be rolled in as a feature, b) spun off as an optional add-on, c) scrapped entirely.
Oh yeah, or d) taken back to the drawing board & re-engineered for another go-round.