Seems to be a risky approach, the signals (pupil dilation, heart rate, etc.) described are ones that are known to be influenced by age, gender, race and medical

Seems to be a risky approach, the signals (pupil dilation, heart rate, etc.) described are ones that are known to be influenced by age, gender, race and medical conditions (including pregnancy). If large companies adopt it, there will almost certainly be lawsuits around it (there are people who will specifically apply for jobs at wealthy reputation-sensitive companies with the primary aim of suing them for discrimination when they get rejected; they often look out for things like this). (for those curious in the US the Uniform Guidelines on Employee Selection Procedures (1978) describe the kind of validation tests you need to do on stuff like this to stay on the right side of the law)