Asking the PFS forum because I'm thinking about it *for* PFS:
Can a Cavalier (Daring Champion) take the Amateur Swashbuckler feat before 4th level? I would say it's reasonable because they don't have Panache *yet*, and stand to benefit from the Extra Panache when they do. By that token, they should probably take Dodging Panache as their 1st level deed so as not to risk the follow-on reasoning that they lose the feat (and therefore, the deed) at 4th.
That said, precedent suggests that a character acts as if they had an ability until their archetype gives said ability away (see Ranger/Paladin spellcasting).
What does the board/campaign think?