Lon is incorrect with this YouTube review, you simply cannot get any Chromecasting working at all without any device being Google Certified. You need legit Googlecasting Keys that have to be supplied by Google.

He is getting Google Certified mixed up with a device being Netflix Approved. That is an entirely seperate issue.

Just because a device is Google certified does not mean it is automatically Netflix approved. There are many set top Google Certified - Android TV, PayTV boxes that are sold with No Netflix Approvals either, some do not get Netflix approved until after initial release.

This KM8 device can dual boot and run LibreELEC Kodi Krypton from a SD card. If you are a "home theatre enthusiast" that combo ticks every box with everything working.

There is NO Android TV external media player that I know of the supports Netflix DD+ > DD audio downmixing, even ones with a Dolby Audio Licence.

You need to use Amazon Fire TV's or the Apple TV's for such (Netflix, Prime Video etc) Dolby Audio downmixing.