[Honor Note 10 Guides, News, & Discussion] ForgottenSolstace:
This thread outlines the exact steps in installing a custom ROM on your Huawei Honor Note 10 device with either EMUI 8 or EMUI 9. You can install and run TWRP on both EMUI and or EMUI 9.

Make sure to follow this guide precisely, as order matters. At the end, I will post an explanation of why we need to execute these steps. I spent an entire weekend of trial and error on my Huawei Honor Note 10, and now I have figured out the ins and outs so you don't have to. You're welcome :cowboy:

Prerequisites

Huawei Honor Note 10 device, either on stock ROM or rooted (doesn't matter)

MicroSD card (formatted exFAT or FAT, doesn't matter)

Bootloader unlock code for Huawei Honor Note 10 (follows a format like my own HBP38K14DBK2RNB4)

Computer with admin privileges

Before You Flash Anything

Back up, back up, back up! I am not responsible if you lose valuable or sensitive data. Your Huawei Honor Note 10 will factory reset a number of times (probably more) before you can get back up and running again. Either use TWRP to do this, or use HiSuite (not recommended but will work on a locked bootloader).

Remove your SIM card! Your carrier may get charged ridiculous amounts of fees if you have a limited data plan, such as 256MB (Canada has notoriously expensive phone plans, so Canadians beware). When you reboot, expect Huawei's stock ROM to use copious amounts of data on retrieving the latest version of bloatware and spyware.

Ensure you have stock recovery installed. If you don't, download the stock recovery image, place it in your Minimal ADB and Fastboot folder, then boot to download mode by holding the VOLUME DOWN button and simultaneously plug in in your Huawei Honor Note 10 device, then open Minimal ADB and Fastboot on your computer and run this command:

fastboot flash recovery_ramdisk RECOVERY_RAMDIS.img

Steps to Install Custom ROM on Huawei Honor Note 10

Download the EMUI 9 stock ROM and place the dload folder on your MicroSD card

Boot to (stock) recovery by holding down the VOLUME UP, VOLUME DOWN, and POWER buttons

at the same time

. The update should begin immediately. Wait patiently for your phone to reboot

Fill out the bloatware questionnaire by Huawei and download any and all updates under Settings. This will ensure you have the latest boot image. You will reboot at least once.

Once you have completed all the updates, reboot to download mode; press and hold the VOLUME DOWN button while you plug in your Huawei Honor Note 10 device to your computer

On your computer, download and open Minimal ADB and Fastboot

Run the following command:

fastboot oem unlock <code>

(where code corresponds to a format that looks like this: HBP38K14DBK2RNB4)

Confirm unlocking your bootloader by using the VOLUME keys, selecting yes, and pressing the POWER button. The Huawei Honor Note 10 device will now perform a factory reset

IMPORTANT step. DO NOT let the Huawei Honor Note 10 reboot.

DO NOT

. Impatiently wait for the low-level factory reset to complete and as soon as it does, enter download mode again by pressing the VOLUME DOWN key and plugging in the device again

Flash this TWRP recovery:

fastboot flash recovery_ramdisk HN10_Twrp.img

Reboot to recovery by holding the VOLUME UP and POWER buttons for over 5 seconds. You should see the TWRP logo, and it should boot up. It should boot up right away, so if TWRP hangs here on the TWRP logo, you need to skip back to step 2

IMPORTANT: wipe to factory reset. Wipe /system again via advanced wipe just to be safe

Install any custom ROM you wish via selecting a system image

IMPORTANT: disable_Dm-Verity_ForceEncrypt by installing this zip. If you don't do this, you won't be able to enter TWRP again

Optionally install magisk, titanium backup, and other magisk mods

Reboot system and profit

Update: 2021-04-06​

Reboot to recovery by holding the VOLUME UP and POWER buttons for over 5 seconds. This should boot you to stock RECOVERY.

Wipe to factory reset. Confirm by typing "yes" (WARNING: this wipes your device)

Plug in your Huawei Honor Note 10 to your PC with ADB

Boot to DOWNLOAD mode by holding down the VOLUME DOWN button as soon as your Huawei Honor Note 10 reboots

Flash this TWRP recovery:

fastboot flash recovery_ramdisk HN10_Twrp.img

Reboot to recovery by holding the VOLUME UP and POWER buttons for over 5 seconds. You should see the TWRP logo, and it should boot up. It should boot up right away, so if TWRP hangs here on the TWRP logo, you need to skip back to step 2

Install any custom ROM you wish via selecting a system image (or zip file if you have EMUI 8)

Install magisk, titanium backup, and other magisk mods (note that you will NOT be able to boot to recovery after this; consider this you last chance to install any mods)

Reboot system and profit

Background and Explanation

When you first flash a ROM, even in EMUI 8, your Huawei Honor Note 10 encrypts /system to prevent third parties such as TWRP from mounting it. Hence, you may successfully boot to TWRP, but /system will be mounted as read-only. This is problematic, as it means you can't install any new ROMs (however, you can make a backup, which can be useful for backing up stock, encrypted /system partitions)

Because /system gets encrypted, it means you have to wipe /system completely. Doing a factory reset (low-level) does this, once you unlock your bootloader. However, if you were to let your Huawei Honor Note 10 boot, then the stock ROM would, by default, encrypt /system, forcing you to start this process all over again (as TWRP will, in most cases, not even boot with an encrypted /system). If your TWRP hangs on the TWRP logo, your /system partition is likely encrypted. You need to factory reset, install TWRP again, and then wipe /system, followed by installing the Disable_Dm-Verity_ForceEncrypt_01.15.2020.zip script.

ROMs I Tested That Work (well)

Resurrection Remix 7 (openKirin)

I hope this guide helps other fellow Huawei Honor Note 10 owners. If you have any questions, please also make sure to include your EMUI version and steps taken so that I can best help you. I hope that I have saved some of you trouble when updating to EMUI 9 and also helped to explain why updating can become so tedious.