Thanks for the lightning quick response (as ever).
Didn't manage to get it to play ball with FileZilla, but did using another client called WinSCP.
Using this I can see that it prompts first for one of the passwords and then the other.
I will be happy to beta test this functionality for you, if you would like?
Great to see that Qlik is still allowing some of the functionality of Qlik Web Connectors to be used for free. I can see my life involving a lot more scripting and windows scheduler events held together with bits of string and sticky tape if QWC FTP wasn't freely available.