Apologies as I am not totally sure if I understood what you are trying to do. Please let me know if my understanding is incorrect so we can provide appropriate responses.
Yes, report fields with values that start with minus (-) and plus (+) will be double-quoted. With this, are you trying to use the double quote (") as the delimiter? Based from what I understood in the
doc, the field is double-quoted to avoid treating the field value as a formula when importing into spreadsheet and thus, if you will have to programmatically parse the line, you would still have to use the comma (,) as the delimiter. Additionally, with my test account, when I generated a report (e.g. report.csv), the double quote is not included in the cell value.
Could you please provide more details on what you wish to achieve so we can investigate further?