The Galaxy Note 8 was the first smartphone from Samsung to be contemplated with Android Oreo, that is, it is at the top of the list of priorities of the manufacturer in the matter of updates.
The phablet was contemplated with another update just now, which brought in addition to the Android security patch for January 2018 (which includes fixes for Specter and Meltdown) a new bootloader.
With the update of the bootloader, Samsung basically prevents the downgrade of the operating system of the smartphone to be performed, but this time, the limitations went much further.
After the update in question, users of the model in question will no longer be able to flash ROMs customized by ODIN, seeing that the smartphone will block any installation that is not signed by Samsung.
The limitation also extends to the exchange of regional ROMs, for example, if your device is made for Chinese market, after the update, you will not be able to flash a ROM of the United Kingdom on it.
If users still attempt to install custom ROMs or from another region, the risk of ‘bricking’ the device is great, and since the new version of bootloaders is not compatible with ODIN, reverting the process is currently impossible.