The question was how often.
Sorry - a bit under the weather. Seems to have messed with my reading abilities.
Is this closing > reapplying for same card or downgrading > applying for new card?
I downgraded and applied the next day with no problem at all. Others I know apply every 8-12 weeks and seem fine. I have read that several ppl have opened, closed and applied again for same cards within a 2 week window.