Data point:
AMS-ZRH-SIN-SUB Star Alliance Ticket

Refund Requested April 3, Acknowledged on May 4, Refund Received on Date of Flight June 2 by the Singapore AMS office.

Interestingly enough though my three separate booking from early April with multiple sectors LAX-SIN , SIN-HKT, HKT-SIN-NRT has yet to be refunded.