FYI.

Byteball's lead developer made a statement on Slack yesterday in the #announcements channel: "The graph is very complex now, which makes validation very slow, and it is still performed in sql. So large complex graph became possible after we allowed spending unconfirmed funds. Trying to do urgent performance improvements now." So it's not the popularity of the Steem attestations but the possibility of spending unconfirmed funds that is the issue here. No ETA for a fix I'm afraid, we just have to be patient. You can join our Slack here.

https://www.reddit.com/r/ByteBall/comments/8yzkq3/is_there_an_official_statement_in_regards_to_the/