[Xiaomi Mi 8 Guides, News, & Discussion] tsongming:
I quickly pieced together an answer for you, keep in mind that this is not a definitive guide. Give me a couple of days and I will try to expand on it by editing this post with more detailed ARB information. Plus, I will link to here from the OP.

Use any of these steps at your own risk,

I own a global version of the Mi8 and will not personally experience the bricking potential that people with the Chinese version of the Mi8 have to worry about.

Regarding 9.3.14 :

Should be fine if you are using the chinese firmware version, I.E: fw_dipper_miui_MI8_*.zip is Xiaomi Mi 8 (dipper) China firmware >>>> Keep in mind that base firmware is really nothing more than just drivers, and radio bands >>>> Get your correct firmware from here: https://xiaomifirmwareupdater.com/#stable

EDIT : See this post too: https://xdaforums.com/showpost.php?p=78911687&postcount=8

Basic ARB Instructions if you have a Chinese device

First ensure that your phone is correctly unlocked with the Xiaomi Unlocking tool, setup your Miui account and use the Miui Forum app and you will get access to better features and themes while using a Miui OS.

The main issue and thing to beware and afraid of is installing a global rom on a Chinese version of the Mi8 … It seems that it is really only an issue If The Bootloader Is Locked or if you try to relock it.

Do not install Global firmware on a locked device or you will have a definite brick.

Make sure that your phone is linked to your account, this way you have complete control. Personally, If I had a device with a vendors account, I would demand a refund either from the vendor or the website dealer.

To Check ARB

Go to fast boot and type in the code "*fast boot*fastboot getvar anti*" on your CMD.

ARB level is max to 1.

AFAIK: Most roms are Arb=1 or Arb=0 so its apparently safe to install those roms.

To be safe, do not mess with ARB always flash rom using Fastboot method.

Paraphrased Excerpt below from user “YoungChaos” (member of MIUI Device Team) rephrased for clarity in English.

Arb is anti-rollback and it's used for security reasons:

It will deny any attempted installation of older firmware, it used for security purposes to prohibit old exploits. ( So he is saying that once you install base firmware, don’t try to install old bad firmware over top of it.)

Re-locking the bootloader, is another thing to to avoid

To avoid brick you CAN-NOT re-lock bootloader with a global rom on a Chinese Phone.

To avoid ARB issues just flash "official" firmware using fastboot ( Firmware is used in this context as the base drivers.)

If using ADB, you will be alerted you if you are risking ARB or not. The Bootloader has a check to protect you from flashing a lower-arb rom , so it will protect you from bricking your device and It will show you an error and you will understand that you cannot flash it.

This may have been updated to include warnings within TWRP. I install almost everything strictly within TWRP…But I have a global device.

I hope this helps you.

Edit:

I have a theory, I believe that the only thing that make the chinese phone and the Global one different is the Radio drivers ( well specifically the modem, or Non.Hlos.Bin image. and vendor files.

On other phones, you can make a Global phone think its a Chinese phone and vice versa. I am wondering if there is maybe a way to a create a flashable file to get around the risk of bricking a Chinese phone. The only differences that I can see between firmwares is with the modem, outside of that it looks identical. If this can be solved, customer roms could be setup to flash certian firmware based on the device ID. Maybe.