Closed Issue: Row insertion very slow [8458]

Row insertion gets progressively slower and slower upon the length of a worksheet getting longer than 20 rows or so. Class is attached. You can simply instantiate an object. parameters to CompareSpreadsheets() are:

spreadsheet1 path, spreadsheet2 path, desired output path, unique column number (Need this to be able to compare identical lines in different spreadsheets.)
Comments: Please try the latest version of ClosedXML (v0.87.1 at this stage). If you still experience the issue, log it on the new GitHub page.