Hello,
 
-The degree symbol can be exported if you copy and paste it in your colModel label property. The html tags for degree in pdf does not work. See the demo link below.
 
-it is not possible programmatically to repeat the header table in excel. You may want to look at this solution here: https://support.office.com/en-us/article/repeat-specific-rows-or-columns-on-every-printed-page-0d6dac43-7ee7-4f34-8b08-ffcc8b022409
 
-by default  a single header is printed repeated in pdf. In your case toprint the multiple headers you will need to use onBeforeExport event in pdf export I recommend you again with google seerch to use the docs – this some times saves a time and effort. See the example below: http://www.guriddo.net/demo/guriddojs/export/headerpdf/

Kind Regards

Will