We really should edit the title of this thread as the stadium is finished now. Or at least it should be, could still be a work in progress like the Yongam race track... hard hats all round, folks.
I think that with a capacity of around 20,000 they can and will go for a sell out via the free voucher route. I'd guess the Suwon fans traveling on the supporter buses will be fine getting in, but I can't see them giving over too many extra sections to the Suwon fans - rather than allocating one whole stand to the away fans as most clubs do, they're giving over just a couple of corner sections to visiting supporters. They'll probably extend it a bit because Suwon will bring a large number and that's guaranteed bodies through the gate, but most of that yellow section behind the goal is guaranteed to be full of families with freebies.