Yifu,
Could you consider every certain amount of chips bought you can give a few gen 2 chips for the inconvenience? Like buy 8 chips get 2 gen2 free...
This would help
But there are no guarantees that these will arrive, could literally be the same thing all over again.. Loads of even later gen 1s and a bunch of late gen 2s.
Obviously it is up to the Group buy organisers, but I'm going to vote YES to a refund.