Having ability to use the current Signed in user is beneficial in cases where we can ensure it is the right person/role in the form, overriding potential dead branches and generally to be precise with conditional actions.
Case scenario:
Owner transitions into Review status
Reviewer can review, comment back or approve back to Owner.
Owner can see the Review state.
Owner wants to progress without Reviewer approval
Transition is formulated based on condition that the current Signed In User is part of the Owner Role.
Kiril Tasev
The in-progress feature supporting Approval Over-rides will accomplish the same result.