Do you know if I can use your file in my Mi8? Or should I get fstab from my mi8 and edit and apply via TWRP?You can try without fresh install. just flash the zip and check if rom reboot well and is encrypted.
Coming back to twrp should also ask your password pin to unlock.
In case that fail you should turn back to format all for clean install.
my guess should go fine first trial if fstab is well modified.
EDIT:
If you flash forceencrypt.zip SEPARATELY from a rom you must MOUNT vendor partition before!
Just concerned as mi8 vs mi8se could be a problem