Hive account@blurt-swap on Hive is owned by me. I made the account because people were sending their SWAP.BLURT to Hive account@blurt-swap, which didn't exist at the time. So I created the account so that I could refund people who were sending their tokens there by mistake.

I still check it once in a while to see if anyone has sent anything to it, and I refund the tokens.

I think that the Hive account@graphene-swap account on Blurt was carried over from Steem during the fork. So the account would belong to the Hive-Engine team. Why they didn't use it and went for blurt-swap instead, I do not know.