How do I set up my source workbook so that the import assumptions tool automatically picks up the correct header column and data columns? I'm using a best-practice, non-modular workbook for the source data, which means there is an 'Up arrow' in column A; is this the cause why the suggested header row in the assumptions input tool is Column A?
Also, I have actual historical data sourced from SAP in a time series format starting in Column J, but the start colum for data import seems to be randomly chosen (starts in column Y)...
The default export heading and first values columns are determined based on an analysis of the content within the export worksheet, so if you've got content in column A (including the Up hyperlink arrow) this will be your default column. The default values column is determined using a similar process, but it's more complicated because it takes into account the need for there to be blocks of non-empty cells containing numerical (i.e. non-text) data.
In any case, the default columns are not overly important because you can easily change them before importing. It's just annoying once you've got used to the system guessing it correctly for you!
If you send a basic example of the export -> import files you're using to support@modano.com, so that we can reproduce the issue, I'll get the engineers to explore making it smarter in your scenario.