Can you charge a Quick Charge 3.0 phone with a Quick Charge 2.0 mains adapter? The Wileyfox Swift 2 is QC3.0 enabled, but the only trusted brand adapter I can get is QC2.0. What happens when you charge a QC3 device using a QC2 adapter?

I noticed several other questions on this StackExchange, but none of them seemed to answer this particular scenario.
From  Qualcomm product manager, responsible for Quick Charge


  Of course, QC3 is backwards compatible to QC2 so your existing QC2 adapter will charge a QC3 phone and vice versa


(Emphasis supplied)

Thanks for asking this, I was under the impression that it is one way compatibility