1. fastboot --verbose -w to wipe ALL data, including userdata and external storage
2. fastboot flash recovery twrp.img
3. fastboot reboot
4. Install custom ROM
5. Download Disable_Dm-Verity_ForceEncrypt_11.02.2020.zip and rename to Disable_Dm-Verity_enForceEncrypt_11.02.2020.zip to ensure forceencrypt is kept
6. Reboot

Updating

1. Install custom ROM
2. Flash Disable_Dm-Verity_enForceEncrypt_11.02.2020.zip again
3. Reboot