The "version" i use is a mix of ServiceNow plugin and parts of Walter Brame's version, so this might not be the ideal way.

But in GeneralPDF - under addHtml i added.

if(element.toString() == "[{!Rotate}]"){

this.document.setPageSize(PageSize.A4.rotate());

this.document.newPage();

}

You could skip the if statement, if it's every page

And then add the following in GeneralForm (if needed)

parsedBody += '{!Rotate}';