Hello Nevil,
Due to the nature of how server actions are served it’s not possible to determine the content length. We are using transfer-encoding=chuncked which is great for buffering especially for large data sources, but this method returns the content length as undefined.
Learn more here:
https://www.httpwatch.com/httpgallery/chunked
So for now it’s not possible to have precise percentage values for the data loading/processing. You can, however check when the status is == executing, so you can show some message or loading animation.