I'm pretty sure that we're unable to surface that specific layer of PID (personally identifiable information). One reason accountID's exist is to specifically help obfuscate sensitive personal info like an email address by replacing it with a psudorandom string. Legislation like GDPR specifically applies this kind of PID and disclosure - it gets complicated really quickly.
@yakingkuo from the Viveport SDK can provide a confirmation as to if our SDK can surface that data.
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