Sure LUKS will do what you tell it. Bitlocker will do what it wants and just use the TPM unless you jump through a bunch of group policy edits and such. But you are correct, I had forgotten it does give you the option to backup the key to a txt file during the installation or initial encryption process :)
The key is inside the TPM.
For LUKS user set the key; for bitlocker, I believe the key is automatically uploaded to either your Microsoft account or you system admin’s account.
Sure LUKS will do what you tell it. Bitlocker will do what it wants and just use the TPM unless you jump through a bunch of group policy edits and such. But you are correct, I had forgotten it does give you the option to backup the key to a txt file during the installation or initial encryption process :)