SEPA transfers have a 100k limit for instant transfer (much less than 30min, I never timed but I've never seen it even take a full 1min). $1 billion would take

SEPA transfers have a 100k limit for instant transfer (much less than 30min, I never timed but I've never seen it even take a full 1min). $1 billion would take a day to clear, but it would still be 100% free. Irreversibility of such a transaction would be ridiculous for all parties involved, of course they don't offer that.