We noticed something during our testing that may be helpful for others as the new Navigation UI starts rolling out as an opt-in feature on 9/29.
If any of your org's roles already have the UI → All Permissions permission enabled, that role will automatically include the new Navigation UI permission during the opt-in period. In other words, those users will immediately see the new UI starting 9/29 without you explicitly adding the new permission.
We discovered this when we enrolled our test org for the beta: a group of our admin users already had access to the new UI even though we hadn't yet assigned the specific new permission. It turned out that because their role had UI → All Permissions, the new Navigation UI permission was included by default.
Something to keep in mind if you want to control the timing of when certain roles gain access.

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Tony Freestone
Contact Center Applications Manager
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