I use Akzo primer and I dimple after priming. I've had no problems at all with the dimpling process damaging the primer.
Everyone has their own preference here, but there's a couple of reasons I prefer to dimple after priming. First, it is much easier to prep your parts (especially if scuffing with scotchbrite adds) without all the dimples. Second, and this is my own silly reasoning, is that if you prime after dimpling you may, very slightly, (fill in) the dimple with primer. Dimpling after gives you a nice full dimple.
Btw. My prep process is scuff with maroon scotchbrite pad and prekote.