Agree - hold off on polishing
I am just finishing my 12 and plan to paint a small amout of trim and polish the rest (against the advice of everyone I have spoken with about it).
Have polished a few places such as under placards, etc. I am using Nuvite C (I think it is) with a large auto buffer and wool pad followed up by Nuvite S with random orbit car polisher and cotton flannel. The areas I have done include vertical stab under N numbers, trim tab under "no push" labels and around fuel filler. They all look absolutely great - even the really thin metal on trim tab. But I see a host of potential problems - extra polish around rivets, in the rivet head shaft holes, etc. if I do eventually paint.
Hoping a pressure washer will help if it comes to that.