На текущий момент уже подумываю реализовать через "приплюсовывание" каждого нового слова (через поиск пробела) до момента превышения 1024...
$tmp = mb_substr($str, 0, $length, $encoding);
return mb_substr($tmp, 0, mb_strripos($tmp, ' ', 0, $encoding), $encoding) ;
$texthtml5 = 'Привет';
$html5 = '<font size="16" face="Times New Roman"><b>TEXT:</b>'.$texthtml5.'</font>';
$wizard = new PHPExcel_Helper_HTML;
$outtexthtml = $wizard->toRichTextObject($html5);
$page->setCellValue("B{$num2}", $outtexthtml);
$objPHPExcel = new PHPExcel();
$texthtml5 = ' text example';
$html5 = 'Some <b>bold</b>'.$texthtml5;
$wizard = new PHPExcel_Helper_HTML;
$objPHPExcel->getActiveSheet()
->setCellValue('A5', $wizard->toRichTextObject($html5));
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel2007');
$objWriter->save('example.xlsx');
HTTP/1.1 200 OK
Date: Sun, 25 Mar 2018 17:16:57 GMT
Content-Type: text/html; charset=UTF-8
Transfer-Encoding: chunked
Connection: keep-alive
Set-Cookie: __cfduid=000000000000000000000; expires=Mon, 25-Mar-19 17:16:53 GMT; path=/; domain=.сайт.ru; HttpOnly; Secure
X-Powered-By: PHP/5.4.30
Expect-CT: max-age=604800, report-uri="https://адрес"
Server: сервер
CF-RAY: 000000000000000-ARN
okokokok