The laser device in Bourne's back
...seems like kind of a fake notion.
So you've got agents who can memorize the license plate numbers of all six cars parked outside, yet they can't memorize a bank account number?
So why plant a device inside of their skin that projects the number on a wall? In case of the unbelievably unlikely event that the agent has amnesia and needs help figuring out who they are?
It's kind of a risk leaving a device in an agent's skin with a bank account and access to half a million dollars. For that kind of risk there must be a reason. What other reasonable explanation is there?