Answers
SBD → STEEM ratio is determined by STEEM's price feed.
STEEM price /SBD (= US $1)I am pretty sure nobody is converting on steemit. Because price of SBD is much higher than $1.
https://steemit.com/kr/@leesunmoo/3kssf9-sbd
https://steemit.com/witness/@teamsteem/what-are-steem-witnesses-and-why-you-should-support-them