Hi all, Therion has been supporting the advanced features of the Proj library for some time now. (Proj's purpose is to do transformations between coordinate systems.) This functionality was disabled by default and you could enable it using 'proj-auto' and 'proj-missing-grid' options in the initialization file. 'proj-auto' lets Proj choose the best transformation and you can set 'proj-missing-grid' to download a grid file (see https://proj.org/usage/transformation.html#grid-based-datum-adjustments) if the transformation needs it; see the therion book for details. The log file lists all the transformations chosen and used at the end. The latest commit (3bc6556) enables this "use the best transformation and download the grids if needed" functionality. We know that automatic downloads are a sensitive issue, but in this case we can trust the Proj library not to do any harm (https://proj.org/usage/network.html) and the user experience is much better. Could you check if this version works well with your data sets? The windows installer is available here: https://github.com/therion/therion/actions/runs/2203811478 (use the msys2 version which uses up-to-date Proj library; you need to be logged in to github to download it). M.