It wont be a surprise for people who used Opensea that posting any big amount of NFTs is a long and painful process. There's no ability to batch create or batch list an items. We used our JS skills and knowledge to facilitate the creation issue a bit, but still there's no way to facilitate the listing process. There's a need to manually approve each item in wallet. So it might be not so impressive milestone for community but its a big step forward to know that we have 500 pigs listed for us.