Good Morning CC

I have a question about using PP with fondant/gumpaste accessories.

I'm making a wedding cake in 2 weeks, 3 tier iced in PP with either gumpaste or fondant sunflowers (haven't decided which to use yet). I keep hearing that you can't cover an iced PP cake with fondant as it will break the fondant down and turn it to goo. My question is can I put gumpaste/fondant flowers on it when I set it up? I'm a bit worried now that my sunflowers will turn to goo.

Could you put the flowers and stuff on at the last second, so that it doesn't break it down?