To make Tableau and Tableau prep more useful, there needs to be an option to bypass the data interpreter and be able to manually choose which line to start importing data for excel spreadsheets.
When working with spreadsheets, often the data doesn't start for a few rows because there are titles or dates or other information at the top of the spreadsheet. Almost 100% of the files my team use look like this. If you are dealing with one file at a time, it isn't a big deal to manually delete the headers, but recently tableau introduced Tableau Prep which includes a feature to do wildcard unions, allowing for potentially hundreds of files with the same schema to be imported at once. However, to make this tool useful, deleting the headers one at a time is not possible for hundreds of files. Currently my team uses Alteryx to prepare data to be ready for tableau and while we want to switch to Tableau Prep, doing so is impossible without the ability to specify a line to start importing. Using tableau data interpreter works for very simple files, but when the data doesn't begin until line 4, 5, 6, or later, due to large amounts of headers, dates, company information, etc. listed at the top of the file, Tableau Data Interpreter consistently fails to be useful. Furthermore, Tableau Data Interpreter does not behave consistently, meaning that one small change in a file can break the whole system unexpectedly.
Also, simply using the default column names (F1, F2, F3) and renaming them doesn't work because the mix of strings and integers means that tableau prep has a hard time allowing calculations unless you make a calculated for each field, convert to a float, and then filter out the headers one at a time. When there are hundreds of columns of numbers in each spreadsheet, this becomes incredibly time consuming and still doesn't achieve a perfect result.
In short, just being able to tell tableau prep/tableau desktop which line to find the data headers would make the tool useable by my team. I've done some searching online and it looks like many others are experiencing the same issue for Tableau Desktop, but I think the need in Tableau Prep is much more pronounced. Tableau Prep looks like an amazing tool and I believe it will have many people switching from Alteryx as long as this one small change is made.
I've attached a screenshot of the feature from Alteryx to illustrate the missing capability.