Thank you for adding a post and for the detailed information, @simoncohen.

The column shows the indication of how much is the amount of estimate converted to the invoice. Removing the column on the invoice isn't available in QuickBooks Online as of the moment.

I understand the importance of removing this column for you and your business. I'll also take note of this and pass along the message to our product engineers. This way, they'll be able to know and consider this on the future updates.

For additional reference about converting estimates to invoices, you can read this article: Convert an estimate into an invoice in QuickBooks Online.

Keep me posted if you have any other questions. I'm always here to help. Have a nice day!