Vulnerabilities certainly do exist, but I’m pretty sure the attacker has to be well-equipped
I’d call it a protection against data getting cracked in a petty theft, but if your attack vector is much more than that, there are other measures you should probably take. I think Clevis also works with Yubikeys and similar, meaning the system won’t decrypt without it plugged in.
Heck, I think I know someone who just keeps their boot partition with the keys on it on a flash drive and hide it on their person.