As far as I could tell, there was every chance for everyone to earn pretty much endless amounts of points by threading in the new boards. Whether you have one active character or three, there's still the same amount of hours in the day for everyone, and whether you wish to spread that time and energy over one character or more should be up to each player.
I don't think there's any need to make this more complicated than it already is. If you post to everything in a swp, you get points. Great! One person happens to have three characters while someone else have one? Keep the option of earning more points based on activity/threads/etc, as was done this time with 'one point per thread in X board' . That evens out the differences and gives everyone equal opportunity for rewards. A person can't be everywhere at once, and a player can't cram endless amounts of characters into an event without losing out on quality in writing - or personal sanity. x3
Personally, I doubt it will get any better if we start looking at amount of characters someone has, because then we might as well consider how many words there was in a post, how many posts were made during the event, how often people logs in and so on and so forth. Some characters won't be involved in a swp event at all, while other's might be in it from start to finish. Having ten characters doesn't mean you will enter everyone into everything, and to have your number of characters counted against you seems very strange to me. This is, after all, a site focused on writing, and I think that it is by our writing and participation that we should be rewarded.
As was done during this swp.
I am personally very pleased with the whole thing, and really look forward to the continuation of the plot! :)