Step 1: Set up an anonymous Proton account.
Step 2: Store the access codes in a KeePass vault.
Step 3: Create a Cryptomator archive containing the KeePass vault, portable keepass, and a video of you showing step by step what to do to access/move/sell the crypto.
Step 4: Record the log in details for the proton account and the cryptomator archive on paper. Seal in a tamper resistance and tamper sealed envelope.
Step 5: Hire a lawyer to provide the sealed envelope to your chosen person(s) in the event of your death.
If you need to update the info you just log on to the proton account and replace the file.
To hack it someone would have to break protons security, cryptomators security, and KeePass security. Especially if you provide the KeePass vault password via another method.
No information about the setup needs to be shared with anyone. All the lawyer knows is that he has an envelope to turn over, and inside it are instructions to your family. Your family doesn't need to know anything.