Pitted roof from rust under vinyl top repair

Many ways to skin a cat... who knows maybe after I put my vinyl top on the filler will crumble out...you don't know till you end up there. :)

I would assess how thin the overall roof skin is, on mine it was in the sail panels or c pillars etc. If the roof is 50% rust and thin Id reskin the thing is really how much skim coat will be in there to basically crumble apart later I'm thinking...