For Malungon-Tampakan Road revert to secondary seems fine as significant sections are still narrow and rough (surface=unpaved still needs to be restored).

Surallah-Banga-Polomolok Road needs to be reviewed as well, afaik there are also some unfinished sections left which make primary classification questionable.

As for Matanao-Columbio-Marbel Road I most recently changed it back to primary myself based on ground survey and local knowledge. Construction has recently been completed and this link is now both the shortest and fastest route from Davao Region to Marbel. Despite still being designated as a provincial road it's built to the same specifications as national highways and conversion has been requested by DPWH RO XI/XII for many years already.