I'm trying to figure out a way to modify the header for the PDFs when I do the export.
Right now the header say something like Yii2 Grid Export (PDF) Grid Export.
Here is the code I'm using to try to modify it:
            'exportConfig' => [
                GridView::PDF => [
                    'label' => 'PDF',
                    'filename' => 'Preceptors',
                    'title' => 'Preceptors',                        
                    'options' => ['title' => 'Preceptor List','author' => 'Me'],                        
                ],
                GridView::CSV => [
                    'label' => 'CSV',
                    'filename' => 'Preceptors',
                    'options' => ['title' => 'Preceptor List'],                                             
                ],
            ],
            'export' => [
                'PDF' => [
                    'options' => [
                        'title' => 'Preceptors',
                        'subject' => 'Preceptors',
                        'author' => 'NYCSPrep CIMS',
                        'keywords' => 'NYCSPrep, preceptors, pdf'
                    ]
                ],
            ],