Capture user identity?

## Background [Optional]
One aspect of 'clarity', auditing & lineage is understanding 'who' ran the query or transformation. Many compliance regimes require knowing who access what and when. Further which spline does is to capture the 'how' of the transformation (or query).

## Question
Does Spline capture any form of user identity, is it feasible to capture the identity and to do so as transparently as possible (e.g. in flight recorder mode) on a multi-tenant cluster (Hadoop or Databricks) ? - Thank you!