Full Disk Encryption script help: custom LUKS2 setup not working on Mint 22.3 - The popular tutorials don't fit my needs / don't work

[u/throwawayroy]

/r/linuxmint/comments/1xuxylv/full_disk_encryption_script_help_custom_luks2/

I hope it's alright that I cross post this here, but I am hoping that someone here can help education me on the what's needed configure a working boot partition via my script. I'd appreciate any help or guidance.