There are some technical issues that it would be good to work out (and perhaps those of us who work in the field might be able to contribute to doing so), but the fact that it fills up so quickly, even in spite of the technical hurdles, tells us that there's a bigger problem of capacity. I know this is a regular subject of discussion, but absent the ability to make the competition itself much larger, it might make sense to have some way to allocate entries besides having the ability to sit in front of a computer and hit "refresh" all afternoon. For example, some kind of lottery - give people a week or two to enter and register, and then randomly choose as many entries as possible from among them.
(I'll also be curious to see the distribution of entries-per-person this year. I don't know how much it would help to dial it back from 15 to, say, 5 or 3, but that should be on the table, even if it makes things like the Ninkasi award less sensible).