Wrong. For example courts have consistently ruled that you can’t be compelled to unlock your phone or decrypt your hard disk if you’re invoking the 5th
This is demonstrably false.
https://arstechnica.com/tech-policy/2020/08/nj-supreme-court...
> inside your head
If it is written down, biometric, etc it does not get protection under the 5th. Those realms are not inside your head, and so they are protected by the 4th, and subject to warrant.