Hi André,
Firstly, may I say that I have lost count of the number of times your numerous posts have dug me out of various holes and difficulties over the years - so thank you retrospectively for the number and the quality of your contributions to this and similar forums.
Secondly, indeed I had already prototyped using the on-premise gateway for direct updates on the SQL server of my VM, (and of course I corrupted the database almost immediately!)
Thank you for the confirmation, and best regards.