Contrary to what has been said, the conference is not open to just anyone. The conference is only open to hair transplant doctors and their staff, guest patients that are involved in the live patient viewing portion of the conference, and exhibitors. The ISHRS does not allow guest patients to roam the halls of the conference and attend presentations, nor is this allowed for exhibitors.
Regarding punch size, you'll be fine at .75mm regarding visible scarring, or the lack thereof. Generally this is the case for punch sizes up to .9mm but exceptions exist above and below this range.