Is it possible to perform a partial roll out in the Chrome web store?

This comment mentions a partial roll out in Chrome Web Store. Where can I find that feature? My extension has more than 8,000 users but I don't see any partial roll out feature and I'm afraid to send the next version to all users at the same time.

I don't think it's documented anywhere. And I was wrong!

Documentation link: Control how fast your app reaches users.
In CWS lingo this is called "Controlled Rollout".

If you don’t see the max deploy percentage control, it may be because of the following:

• You have less than 10,000 users. Currently the “controlled rollout” feature is only available for items with at least 10,000 users.
• You need to upload a newer (higher) version of a package to use the “controlled rollout” feature. We can’t apply a controlled rollout to an already published package, because it may have already reached 100% of users.

It should show on the Edit page after you upload a new version that's not published yet. Here's a mention of it and how it should look:

Also, I've never actually tried using it.

Update: In the new Webstore Dashboard it's called "Partial Rollout" and has the same 10k users requirement.