our school went to partially structured because a lot of girls couldn't make some of the required parties so they had to drop out. With the passport they still have to visit every house before they can be invited back to any philanthropy parties but they can do it on their own time. All chapters had the same hours for the parties and the PNMs had three days to go to each house. It worked out well for us this year, we took the most new members so that was exciting
I know I had to drop formal because I couldn't attend a couple of the parties. We have a lot of people who work or take night classes so I think it works out better.
To know who was there we gave each girl a name tag and then collected it when she left and stuck it in a book. Also, each active was given a notebook to write down what they could about the PNMs they had talked to because there were some who came to the first party on Sunday but we didn't know who was going to be continuing until Thursday I think it was so it was helpful to remember who was there and what they were like and such.