I use it for storing luks credentials, so every time I boot I get dropped at my login manager. It leaves my system vunerable to attacks to it, but its quite convenient.
Besides, if anyone tries to boot any other OS which is not mine, the keys are erased.
It talsk about pcr, every time another OS is booted some pcsrs are changed, and if the keys are installed on the correct ones, this will lead to it being erased