You need Netflix in HD, you use the M-Pencil frequently, or you cannot afford to replace a bricked tablet.

adb reboot bootloader

The phrase is a dangerous keyword. While cracked bootloaders exist via paid Russian/Chinese engineering tools, the era of free, easy custom ROMs on Huawei died in 2019. Proceed with extreme caution, back up your stock firmware (using Huawei Multi-Tool), and never trust an executable from a random forum.

fastboot erase system fastboot flash system name_of_rom.img