Thanks for the data point. If you wish to pay in HKD, you can do so via expedia.com.hk .
Just be aware that:
1. Sometimes for HKD there is a pricing anomaly, making tickets much more expensive (as of March 2019)
2. Expedia usually need me to stay 1 hour on the phone to check the refund rules and start the refund process. If you can expedia.com.hk during the weekend, you need to provide Aeroflot's Russian phone number to the agent.