Thanks for all these pointers. I keep following in your footsteps. After much fiddling, I managed to get all the fields into Redash directly from Central via the Odata. Separating lat and lon values from within a question group was especially tricky, but I got it working. Then I discover that Redash only offers core SQlite functions and there is no power function (which is essential for using tree allometry). Now looking into how to add math functions to SQlite, but of course docker adds a layer of complexity.