Hi Roman,
The IMA SDK for tvOS version 4.4.2 uses the UI Focus Environment protocol to manage when the ad overlay requires focus. You can see a simple implementation on lines 106-115 of our latest swift sample. When Ads are being played, the focus needs to be set on the Ad display container's focus environment, as seen in that sample. However, when ads are not being played, the focus can be put on any view controller, as dictated by your implementation.
I hope this answers your question.
Thanks,
Greg Schoppe
IMA SDK Team
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