Practical considerations aside for the moment, I'm a bit put off by the concept.
TSA/DHS: "We realize that we have created a nightmare for travelers. For lots of reasons, we make people wait a long time at some locations (especially when returning from overseas). Yes,we could make it faster and more efficient, I suppose. Would you like special consideration and a shorter line? Pay us $100. It is up to you."
It only sounds like a "protection racket".
The government has all the information they need to speed me through security, already collected and compiled by other government people at taxpayer expense. Bundling it up for use by TSA/DHS should be on their dime, and a normal part of the process to ID "undesirables" and to reduce the screening time of those who are "okay."
"Freedom begins when you tell Mrs. Grundy to go fly a kite." - R. Heinlein