You can hide the “FileVault Preboot from Preboot” with a few lines of code in the config.plist and the Clover Configurator app or remove (caution as there isn’t an undo function) FileVault Preboot from Preboot safely for a clean look in your theme when it launches.
00:00 – Clover Boot Manager
01:10 – Open Terminal
01:30 – Type in
diskutil apfs deleteVolume Preboot
02:00 – If you prefer, you can clear the terminal or bash history
02:15 – Restart macOS and confirm the changes.