I take it you're not a security researcher either, because "A properly encrypted device is a brick if stolen, which is the only reason to have full disk encrypt

I take it you're not a security researcher either, because "A properly encrypted device is a brick if stolen, which is the only reason to have full disk encryption in the first place" is insufficient, too. Cold boot attacks, copying the drive and hacking the bootloader to get the drive password the next time you log in are two trivial methods, both of which have been used already. Once you lose physical access to your hardware, it's game over. You simply cannot trust your computer after that point if you care AT ALL about maximizing security.