Hi,
I noticed an oddity which I might have reported before. If the table reader has not finished generating a preview but transformation, like excluding a column from the import, then triggering the import while the preview is still generated, the column is still imported.
After waiting for the preview gettign generated. If there are a lot of files to be processed, preview generation can take quite some time. Adding an option to limit the preview generation or always importing based on the defined transformation, would reduce chances of errors.
Best
Mike