From what I heard, updates for many established developers, even individuals, go through within a few hours.

I'd also love the ability to take back control over my rollouts, but with Apple's recent crackdown on remote controlled feature flags in response to fraudulent nudification apps, I'd be very careful about this.

Rumors say Apple now uses heuristics to detect feature flags in the binary. While that's not directly relevant to remotely delivered JS, I fear that bypassing App Review in this way could become a quick ticket to account termination.