Assume that there are generally two kinds of physical attackers:
* Casual, opportunistic attackers who will steal any available laptop.
* Targeted attackers who want your laptop in particular.
Against a casual attacker, even if your laptop is stolen unlocked, it's not going to be carefully kept unlocked. Doing so requires sophistication, care, and extra risk. Instead, the laptop is just going to get wiped.
Against a targeted attacker, like the FBI when they took down Ross Ulbricht (who FDE'd his laptop), the attacker will simply wait until the laptop is unlocked.
* Casual, opportunistic attackers who will steal any available laptop.
* Targeted attackers who want your laptop in particular.
Against a casual attacker, even if your laptop is stolen unlocked, it's not going to be carefully kept unlocked. Doing so requires sophistication, care, and extra risk. Instead, the laptop is just going to get wiped.
Against a targeted attacker, like the FBI when they took down Ross Ulbricht (who FDE'd his laptop), the attacker will simply wait until the laptop is unlocked.