Installing a custom ROM on the Huawei MatePad 10.4 is extremely difficult because Huawei officially stopped providing bootloader unlock codes in July 2018. Without an unlocked bootloader, you cannot natively flash third-party operating systems like LineageOS or Pixel Experience.
Compatibility: Models like the BAH3-W09 and BAH3-L09 are the primary targets for these attempts. huawei matepad 10.4 custom rom
Compatibility notes
and allows you to run Google apps alongside your standard Huawei apps. GBox / GSpace : These are popular "sandboxed" applications found on the Huawei AppGallery Installing a custom ROM on the Huawei MatePad 10