The Pure currently does not enable blocking numbers.

Blocked Numbers Don't Transfer

While it's possible that the option to block specific numbers may be added to the Pure with future updates, information about blocked numbers still wouldn't transfer to the phone when importing contacts. Assuming this feature gets implemented, users would have to manually set all blocked numbers on the Pure.

We're unable to provide any specifics on when blocking numbers may get implemented

Worth Knowing

Generally speaking, blocked numbers usually don't get transfered between phones and users need to set them up anew in most cases when switching devices. The exception to this are Apple users switching from one iPhone to another (they can synchronise blocked contacts through iCloud). This option is not available for Android users or when switching from an Android phone to an Apple device.