This may be a completely stupid idea and perhaps too late to implement, but I think it would work out. Instead of an unofficial consolation round, there could be an official competition with just 1 round of 3x3 running parallel to the main competition. In that way, those who didn't make it to the second round, can still do an official average. The room is there, the equipment is there and looking through the psych sheet, there are enough delegates who are unlikely to make it to the second round and who could act as delegates for this parallel competition. Much of the logistics is already done, so organisation wise, it's not that much work on top of what has already been done. It's mainly an admin matter. As far as I know, there is nothing in the WCA Regulations, which prohibits multiple competitions happening in one venue at the same time.
But as I said, it might be completely stupid but it's an idea.