I was thinking maybe that meant an older version had a limit of 1024, but according to https://www.askingbox.com/info/xls-and-xlsx-maximum-number-of-columns-and

I was thinking maybe that meant an older version had a limit of 1024, but according to https://www.askingbox.com/info/xls-and-xlsx-maximum-number-of-columns-and-rows https://www.askingbox.com/info/xls-and-xlsx-maximum-number-o... it has always been 256 for .xls and 16384 for .xlsx.