Add suggested buyer to the requisitions

Dears

Please advise if there any function or method to add a suggested buyer to the requisitions, neither than:

1- Suggested buyer field in delivery information in requisition page.

2- The default buyer for the category i buyers page.

The situation is I have a requisition with a suggested buyer, but it's not filled by the previous functions, because for the first point; this field is hidden using personalization. For the second point; the requested category in the requisition isn't assigned to the buyer as a default category.

Regards