File this one under things finally working as described.
If you've ever mashed that "Check for update" button in your phone settings because you were waiting and ready for an update, you know disappointment. You might be disappointed less in the future, as the button now actually checks for an update when asks rather than check to see if you were slotted in to be updated that day.
Long-time Android developer and new master of update buttons Elliot Hughes took to Google+ today to explain the changes.
When a device checks in because you've specifically asked it to, we flag that this is user-initiated and so you're not subject to the usual limitations. So even if we're at 1% rollout and 1% of users already have the update, if you manually check you'll still be offered it, even though a background check at the same time wouldn't.
You'll need the latest version of Google Play Services, and it appears that this feature may be for Oreo and higher based on comments. We've reached out to Google and will update with more when we hear back.
It's also worth noting that this only applies to OS updates. Apps will still have a gradual rollout as decided by the developer, even Google's apps. Even Google Play Services, which you need the latest version of for this to work as intended. That would be the one dated September 5, 2017, and the version number varies by device.
It's also worth noting that doing this means you might be someone who gets to witness the next bug firsthand. Gradual rollouts are done so that any bugs that weren't found during testing won't affect many devices before the rollout can be stopped and the software fixed. Impatience is often rewarded!
So go ahead and hit the button if you're waiting for the September patch and let everyone know if it worked.